Serine hydroxymethyltransferase

Last updated
Serine hydroxymethyltransferase
6m5w2.jpg
Serine hydroxymethyltransferase 1 (cytosolic), homotetramer, Human
Identifiers
EC no. 2.1.2.1
CAS no. 9029-83-8
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Search
PMC articles
PubMed articles
NCBI proteins
PyMol rendered crystal structure of serine hydroxymethyltransferase EcSHMTPyMol.png
PyMol rendered crystal structure of serine hydroxymethyltransferase

Serine hydroxymethyltransferase (SHMT) is a pyridoxal phosphate (PLP) (Vitamin B6) dependent enzyme (EC 2.1.2.1) which plays an important role in cellular one-carbon pathways by catalyzing the reversible, simultaneous conversions of L-serine to glycine and tetrahydrofolate (THF) to 5,10-methylenetetrahydrofolate (5,10-CH2-THF). [1] This reaction provides the largest part of the one-carbon units available to the cell. [2]

Contents

Structure

The structure of the SHMT monomer is similar across prokaryotes and eukaryotes, but whereas the active enzyme is a dimer in prokaryotes, the enzyme exists as a tetramer in eukaryotic cells, though the evolutionary basis for this difference in structure is unknown. [1] However, the evolutionary path taken by SHMT going from prokaryotic dimeric form to the eukaryotic tetrameric form can be easily seen as a sort of doubling event. In other words, the eukaryotic SHMT tetramer resembles two prokaryotic dimers that have packed together, forming what has been described as a “dimer of dimers.” [3] The interaction between two monomers within a dimer subunit has been found to occur over a greater contact area and is thus much tighter than the interaction between the two dimers. [3] Human serine hydroxymethyltransferase 2 (SHMT2) regulates one-carbon transfer reactions required for amino acid and nucleotide metabolism, and the regulated switch between dimeric and tetrameric forms of SHMT2, which is induced by pyridoxal phosphate, [4] has recently been shown to be involved in regulation of the BRISC deubiquitylase complex, linking metabolism to inflammation. The SHMT2 dimer, but not the PLP-bound tetramer, is a potent inhibitor of the multimeric BRISC complex, revealing a potential mechanism for SHMT2 regulation of inflammation. [5]

A single SHMT monomer can be subdivided into three domains: an N-terminus “arm,” a “large” domain, and a “small” domain. [3] The N-terminus arm appears to maintain the tight interaction between two monomers. The arm, consisting of two alpha helices and a beta sheet, wraps around the other monomer when in oligomeric form. [3] The “large” domain contains the PLP binding site, as seen in other PLP-dependent proteins, like aspartate aminotransferase. [3] The large domain in the eukaryotic form also contains a histidine that is essential for tetramer stability. [3] All four histidines of these residues, one from each monomer, sit at the center of the tetrameric complex, where two histidines from a dimeric subunit engages in stacking interactions with the histidines of the other subunit. [3] Prokaryotic SHMT has a proline residue rather than histidine in the equivalent position, which would in part explain why prokaryotic SHMT does not form tetramers. [6]

The active site structure is highly conserved across eukaryotic and prokaryotic forms. The PLP is anchored by means of a lysine, which forms an aldimine Schiff base linkage with the PLP aldehyde. [7] It has been hypothesized that a nearby tyrosine functions as the proton donor and acceptor during the transadimination step as well as the formyl transfer step and that an arginine residue engages the tyrosine side chain in a cation–π interaction, which helps to lower the pKa of the tyrosine, lowering the barrier for proton transfer. [7]

Mechanism

The mechanism commonly ascribed to SHMT enzymatic activity is a transamidation followed by a cleavage of amino acid side chain from the backbone. [7] The N-terminal amine of serine makes a nucleophilic attack on the aldimine between the SHMT lysine (Internal Aldimine) and the PLP aldehyde to form a gem-diamine, and then the N-terminal amine lone pair comes down to displace the lysine, forming a new aldimine, this time with the serine (External Aldimine). [7] [8] It is believed that a nearby tyrosine is responsible for much of the proton transfers that occur during the transaldimination. [7] [9] [10]

A glutamate in the SHMT active site deprotonates the serine hydroxyl from the external aldimine forming a formaldehyde intermediate. Tetrahydrofolate (THF) then attacks the formaldehyde forming a carbinolamine followed by several proton transfers and dehydration of the carbinolamine, all steps facilitated by the enzyme. The methylene-THF intermediate cyclizes to 5,10-CH2-THF. Lastly, the glycine external aldimine reforms before hydrolysis and release from the active site. Serine hydroxymethyltransferase formaldehyde intermediate mechanism.svg
A glutamate in the SHMT active site deprotonates the serine hydroxyl from the external aldimine forming a formaldehyde intermediate. Tetrahydrofolate (THF) then attacks the formaldehyde forming a carbinolamine followed by several proton transfers and dehydration of the carbinolamine, all steps facilitated by the enzyme. The methylene-THF intermediate cyclizes to 5,10-CH2-THF. Lastly, the glycine external aldimine reforms before hydrolysis and release from the active site.

Once the serine is bonded to PLP, PLP triggers the α-elimination of the hydroxymethyl group of the substrate (serine). This group is released as a formaldehyde molecule because a nearby glutamate abstracts the proton from the hydroxyl group. Afterwards, the nucleophilic amine on THF attacks the free formaldehyde intermediate to make the carbinolamine intermediate. [8] [12] In the second case, the nucleophilic amines on THF attack the serine side chain carbon, simultaneously forming a carbinolamine intermediate on the THF and a quinoid intermediate with the PLP. [8] [13] However, THF is not an obligate substrate for SHMT, meaning the cleavage of serine and other β-hydroxy amino acids (such as threonine) can occur without the presence of THF and, in this case, the mechanism is a retro-aldol cleavage. [14] Also, it seems that the subsequent dehydration of the carbinolamine intermediate to form the methylene bridge and fully cyclize into 5,10-CH2-THF is not catalyzed by the enzyme and this reaction may occur spontaneously. [8] In fact, this conversion could occur outside the enzyme, but a study shows that this reaction is faster and thermodynamically favourable when occurs inside the SHMT aided by the Glu57 residue. Moreover, the cyclisation of the carbinolamine intermediate to form 5,10-CH2-THF is essential to Glu57 restore its proton that is used to protonate the quinonoid intermediate and complete the catalytic cycle. [12]

Clinical significance

Folate metabolism has already been the subject of chemotherapeutic strategies, but SHMT inhibition, while researched, had not really been taken advantage of in commercial anticancer drugs. [15] However, because the folates used by folate metabolic and folate-dependent enzymes are all very similar in structure and folate mimics are already common in medical use, it has not been difficult to find potential molecular structures that may inhibit SHMT. [15] For example, pemetrexed is already used as an antifolate to treat mesothelioma and was found to be an effective inhibitor of SHMT [15] and screening other antifolates revealed lometrexol as another effective inhibitor of SHMT. [16]

SHMT has also undergone investigation as a potential target for antimalarial drugs. Research indicates that the active site environment of Plasmodium SHMTs (PSHMTs) differs from that of human cytosolic SHMT, allowing for the possibility of selective inhibition of PSHMT and, thus, the treatment of malaria infections. [17] In particular, certain pyrazolopyran molecules have been shown to have a selective nanomolar efficacy against PSHMTs. Poor pharmacokinetics, however, have prevented these pyrazolopyrans from being effective in living models. [18]

Isoforms

Bacteria such as Escherichia coli and Bacillus stearothermophilus have versions of this enzyme and there appear to be two isoforms of SHMT in mammals, one in the cytoplasm (cSHMT) and another in the mitochondria (mSHMT). [1] Plants may have an additional SHMT isoform within chloroplasts. [19]

In mammals, the enzyme is a tetramer of four identical subunits of approximately 50,000 daltons each. The intact holoenzyme has a molecular weight of approximately 200,000 daltons and incorporates four molecules of PLP as a coenzyme. [20]

Other reactions

As well as its primary role in folate metabolism, SHMT also catalyzes other reactions that may be biologically significant, including the conversion of 5,10-Methenyltetrahydrofolate to 10-Formyltetrahydrofolate. [2] When coupled with C1-tetrahydrofolate synthase and tetrahydropteroate, cSHMT also catalyzes the conversion of formate to serine. [2]

Role in Smith–Magenis syndrome

Smith–Magenis syndrome (SMS) is a rare disorder that manifests as a complex set of traits including facial abnormalities, unusual behaviors, and developmental delay. [21] It results from an interstitial deletion within chromosome 17p11.2, including the cSHMT gene and a small study showed SHMT activity in SMS patients was ~50% of normal. [21] Reduced SHMT would result in a reduced glycine pool, which could affect the nervous system by reducing the functioning of NMDA receptors. This could be a potential mechanism for explaining SMS. [21]

Figures

Biological role of SHMT:
a) Serine-glycine interconversion catalyzed by SHMT. THF = tetrahydrofolate, CH2-THF = N-5,N-10-methylenetetrahydrofolate. The red dot highlights the carbon that is transferred from Ser to THF.
b) Schematic overview of human SHMT (hSHMT) function. MTHFD = methylenetetrahydrofolate dehydrogenase-cyclohydrolase, CH2-THF = N-5,N-10-methylenetetrahydrofolate, CH+-THF = 5,10-methenyltetrahydrofolate, CHO-THF = 10-formyltetrahydrofolate, NADP+ = Nicotinamide adenine dinucleotide phosphate, NADPH = NADP+ reduced form.
c) SHMT, dihydrofolate reductase (DHFR), and thymidylate synthase (TS) in the folate cycle. THF = tetrahydrofolate, CH2-THF = 5,10-methylenetetrahydrofolate, DHF = dihydrofolate, FdUMP = fluorodeoxyuridine-5'-monophosphate, dUMP = deoxyuridine monophosphate, dTMP = deoxythymidine monophosphate.
From Nonaka et al., 2019. Biological role of serine hydroxymethyltransferase.png
Biological role of SHMT:
a) Serine–glycine interconversion catalyzed by SHMT. THF = tetrahydrofolate, CH2-THF = N-5,N-10-methylenetetrahydrofolate. The red dot highlights the carbon that is transferred from Ser to THF.
b) Schematic overview of human SHMT (hSHMT) function. MTHFD = methylenetetrahydrofolate dehydrogenase-cyclohydrolase, CH2-THF = N-5,N-10-methylenetetrahydrofolate, CH+-THF = 5,10-methenyltetrahydrofolate, CHO-THF = 10-formyltetrahydrofolate, NADP+ = Nicotinamide adenine dinucleotide phosphate, NADPH = NADP+ reduced form.
c) SHMT, dihydrofolate reductase (DHFR), and thymidylate synthase (TS) in the folate cycle. THF = tetrahydrofolate, CH2-THF = 5,10-methylenetetrahydrofolate, DHF = dihydrofolate, FdUMP = fluorodeoxyuridine-5′-monophosphate, dUMP = deoxyuridine monophosphate, dTMP = deoxythymidine monophosphate.
From Nonaka et al., 2019.

Related Research Articles

<span class="mw-page-title-main">Folate</span> Vitamin B9; nutrient essential for DNA synthesis

Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and storage. Folate is required for the body to make DNA and RNA and metabolise amino acids necessary for cell division. As the human body cannot make folate, it is required in the diet, making it an essential nutrient. It occurs naturally in many foods. The recommended adult daily intake of folate in the U.S. is 400 micrograms from foods or dietary supplements.

Serine is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, a carboxyl group, and a side chain consisting of a hydroxymethyl group, classifying it as a polar amino acid. It can be synthesized in the human body under normal physiological circumstances, making it a nonessential amino acid. It is encoded by the codons UCU, UCC, UCA, UCG, AGU and AGC.

<span class="mw-page-title-main">Pyridoxal phosphate</span> Active form of vitamin B6

Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates.

<span class="mw-page-title-main">Aspartate transaminase</span> Enzyme involved in amino acid metabolism

Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or (serum) glutamic oxaloacetic transaminase, is a pyridoxal phosphate (PLP)-dependent transaminase enzyme that was first described by Arthur Karmen and colleagues in 1954. AST catalyzes the reversible transfer of an α-amino group between aspartate and glutamate and, as such, is an important enzyme in amino acid metabolism. AST is found in the liver, heart, skeletal muscle, kidneys, brain, red blood cells and gall bladder. Serum AST level, serum ALT level, and their ratio are commonly measured clinically as biomarkers for liver health. The tests are part of blood panels.

<span class="mw-page-title-main">Histidine decarboxylase</span> Enzyme that converts histidine to histamine

The enzyme histidine decarboxylase is transcribed on chromosome 15, region q21.1-21.2, and catalyzes the decarboxylation of histidine to form histamine. In mammals, histamine is an important biogenic amine with regulatory roles in neurotransmission, gastric acid secretion and immune response. Histidine decarboxylase is the sole member of the histamine synthesis pathway, producing histamine in a one-step reaction. Histamine cannot be generated by any other known enzyme. HDC is therefore the primary source of histamine in most mammals and eukaryotes. The enzyme employs a pyridoxal 5'-phosphate (PLP) cofactor, in similarity to many amino acid decarboxylases. Eukaryotes, as well as gram-negative bacteria share a common HDC, while gram-positive bacteria employ an evolutionarily unrelated pyruvoyl-dependent HDC. In humans, histidine decarboxylase is encoded by the HDC gene.

<span class="mw-page-title-main">Tetrahydrofolic acid</span> Chemical compound

Tetrahydrofolic acid (THFA), or tetrahydrofolate, is a folic acid derivative.

<span class="mw-page-title-main">Cystathionine beta synthase</span> Mammalian protein found in humans

Cystathionine-β-synthase, also known as CBS, is an enzyme (EC 4.2.1.22) that in humans is encoded by the CBS gene. It catalyzes the first step of the transsulfuration pathway, from homocysteine to cystathionine:

<span class="mw-page-title-main">Serine dehydratase</span>

Serine dehydratase or L-serine ammonia lyase (SDH) is in the β-family of pyridoxal phosphate-dependent (PLP) enzymes. SDH is found widely in nature, but its structure and properties vary among species. SDH is found in yeast, bacteria, and the cytoplasm of mammalian hepatocytes. SDH catalyzes the deamination of L-serine to yield pyruvate, with the release of ammonia.

<span class="mw-page-title-main">Cystathionine gamma-lyase</span> Protein-coding gene in the species Homo sapiens

The enzyme cystathionine γ-lyase (EC 4.4.1.1, CTH or CSE; also cystathionase; systematic name L-cystathionine cysteine-lyase (deaminating; 2-oxobutanoate-forming)) breaks down cystathionine into cysteine, 2-oxobutanoate (α-ketobutyrate), and ammonia:

<span class="mw-page-title-main">5,10-Methylenetetrahydrofolate</span> Chemical compound

5,10-Methylenetetrahydrofolate (N5,N10-Methylenetetrahydrofolate; 5,10-CH2-THF) is cofactor in several biochemical reactions. It exists in nature as the diastereoisomer [6R]-5,10-methylene-THF.

<span class="mw-page-title-main">Cystathionine beta-lyase</span> Enzyme

Cystathionine beta-lyase, also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction

In enzymology, a formimidoyltetrahydrofolate cyclodeaminase (EC 4.3.1.4) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Antifolate</span> Class of antimetabolite medications

Antifolates are a class of antimetabolite medications that antagonise (that is, block) the actions of folic acid (vitamin B9). Folic acid's primary function in the body is as a cofactor to various methyltransferases involved in serine, methionine, thymidine and purine biosynthesis. Consequently, antifolates inhibit cell division, DNA/RNA synthesis and repair and protein synthesis. Some such as proguanil, pyrimethamine and trimethoprim selectively inhibit folate's actions in microbial organisms such as bacteria, protozoa and fungi. The majority of antifolates work by inhibiting dihydrofolate reductase (DHFR).

In enzymology, a D-alanine 2-hydroxymethyltransferase (EC 2.1.2.7) is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">Arginine decarboxylase</span>

The enzyme Acid-Induced Arginine Decarboxylase (AdiA), also commonly referred to as arginine decarboxylase, catalyzes the conversion of L-arginine into agmatine and carbon dioxide. The process consumes a proton in the decarboxylation and employs a pyridoxal-5'-phosphate (PLP) cofactor, similar to other enzymes involved in amino acid metabolism, such as ornithine decarboxylase and glutamine decarboxylase. It is found in bacteria and virus, though most research has so far focused on forms of the enzyme in bacteria. During the AdiA catalyzed decarboxylation of arginine, the necessary proton is consumed from the cell cytoplasm which helps to prevent the over-accumulation of protons inside the cell and serves to increase the intracellular pH. Arginine decarboxylase is part of an enzymatic system in Escherichia coli, Salmonella Typhimurium, and methane-producing bacteria Methanococcus jannaschii that makes these organisms acid resistant and allows them to survive under highly acidic medium.

<span class="mw-page-title-main">Diaminopimelate decarboxylase</span> Enzyme decarboxylates diaminopimelate, forming L-lysine

The enzyme diaminopimelate decarboxylase (EC 4.1.1.20) catalyzes the cleavage of carbon-carbon bonds in meso 2,6 diaminoheptanedioate to produce CO2 and L-lysine, the essential amino acid. It employs the cofactor pyridoxal phosphate, also known as PLP, which participates in numerous enzymatic transamination, decarboxylation and deamination reactions.

<span class="mw-page-title-main">Serine C-palmitoyltransferase</span>

In enzymology, a serine C-palmitoyltransferase (EC 2.3.1.50) is an enzyme that catalyzes the chemical reaction:

<span class="mw-page-title-main">Phosphoribosylglycinamide formyltransferase</span>

Phosphoribosylglycinamide formyltransferase (EC 2.1.2.2), also known as glycinamide ribonucleotide transformylase (GAR Tfase), is an enzyme with systematic name 10-formyltetrahydrofolate:5'-phosphoribosylglycinamide N-formyltransferase. This enzyme catalyses the following chemical reaction

<span class="mw-page-title-main">Cys/Met metabolism PLP-dependent enzyme family</span>

In molecular biology, the Cys/Met metabolism PLP-dependent enzyme family is a family of proteins including enzymes involved in cysteine and methionine metabolism which use PLP (pyridoxal-5'-phosphate) as a cofactor.

Riboflavin-responsive exercise intolerance is a rare disorder caused by mutations of the SLC25A32 gene that encodes the mitochondrial folate transporter. Patients suffer from exercise intolerance and may have disrupted motor function.

References

  1. 1 2 3 Appaji Rao N, Ambili M, Jala VR, Subramanya HS, Savithri HS (April 2003). "Structure-function relationship in serine hydroxymethyltransferase". Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 1647 (1–2): 24–29. doi:10.1016/s1570-9639(03)00043-8. PMID   12686103.
  2. 1 2 3 Stover P, Schirch V (August 1990). "Serine hydroxymethyltransferase catalyzes the hydrolysis of 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate". The Journal of Biological Chemistry. 265 (24): 14227–14233. doi: 10.1016/S0021-9258(18)77290-6 . PMID   2201683.
  3. 1 2 3 4 5 6 7 Renwick SB, Snell K, Baumann U (September 1998). "The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy". Structure. 6 (9): 1105–1116. doi: 10.1016/s0969-2126(98)00112-9 . PMID   9753690.
  4. Giardina G, Brunotti P, Fiascarelli A, Cicalini A, Costa MG, Buckle AM, et al. (April 2015). "How pyridoxal 5'-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state". The FEBS Journal. 282 (7): 1225–1241. doi: 10.1111/febs.13211 . PMID   25619277. S2CID   11561274.
  5. Eyers PA, Murphy JM (November 2016). "The evolving world of pseudoenzymes: proteins, prejudice and zombies". BMC Biology. 14 (1): 98. Bibcode:2019Natur.570..194W. doi:10.1038/s41586-019-1232-1. PMC   5106787 . PMID   27835992.
  6. Scarsdale JN, Radaev S, Kazanina G, Schirch V, Wright HT (February 2000). "Crystal structure at 2.4 A resolution of E. coli serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate". Journal of Molecular Biology. 296 (1): 155–168. doi:10.1006/jmbi.1999.3453. PMID   10656824.
  7. 1 2 3 4 5 Florio R, di Salvo ML, Vivoli M, Contestabile R (November 2011). "Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies". Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 1814 (11): 1489–1496. doi:10.1016/j.bbapap.2010.10.010. PMID   21059411.
  8. 1 2 3 4 5 Schirch V, Szebenyi DM (October 2005). "Serine hydroxymethyltransferase revisited". Current Opinion in Chemical Biology. 9 (5): 482–487. doi:10.1016/j.cbpa.2005.08.017. PMID   16125438.
  9. Oliveira EF, Cerqueira NM, Fernandes PA, Ramos MJ (October 2011). "Mechanism of formation of the internal aldimine in pyridoxal 5'-phosphate-dependent enzymes". Journal of the American Chemical Society. 133 (39): 15496–15505. doi:10.1021/ja204229m. PMID   21854048.
  10. Cerqueira NM, Fernandes PA, Ramos MJ (May 2011). "Computational Mechanistic Studies Addressed to the Transimination Reaction Present in All Pyridoxal 5'-Phosphate-Requiring Enzymes". Journal of Chemical Theory and Computation. 7 (5): 1356–1368. doi:10.1021/ct1002219. PMID   26610130.
  11. Trivedi V, Gupta A, Jala VR, Saravanan P, Rao GS, Rao NA, et al. (May 2002). "Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus: insights into the catalytic mechanism". The Journal of Biological Chemistry. 277 (19): 17161–17169. doi: 10.1074/jbc.M111976200 . PMID   11877399.
  12. 1 2 3 Fernandes HS, Ramos MJ, Cerqueira NM (2018-10-03). "Catalytic Mechanism of the Serine Hydroxymethyltransferase: A Computational ONIOM QM/MM Study". ACS Catalysis. 8 (11): 10096–10110. doi:10.1021/acscatal.8b02321. ISSN   2155-5435. S2CID   105838672.
  13. Szebenyi DM, Musayev FN, di Salvo ML, Safo MK, Schirch V (June 2004). "Serine hydroxymethyltransferase: role of glu75 and evidence that serine is cleaved by a retroaldol mechanism". Biochemistry. 43 (22): 6865–6876. doi:10.1021/bi049791y. PMID   15170323.
  14. Chiba Y, Terada T, Kameya M, Shimizu K, Arai H, Ishii M, Igarashi Y (February 2012). "Mechanism for folate-independent aldolase reaction catalyzed by serine hydroxymethyltransferase". The FEBS Journal. 279 (3): 504–514. doi: 10.1111/j.1742-4658.2011.08443.x . PMID   22141341.
  15. 1 2 3 Daidone F, Florio R, Rinaldo S, Contestabile R, di Salvo ML, Cutruzzolà F, et al. (May 2011). "In silico and in vitro validation of serine hydroxymethyltransferase as a chemotherapeutic target of the antifolate drug pemetrexed". European Journal of Medicinal Chemistry. 46 (5): 1616–1621. doi:10.1016/j.ejmech.2011.02.009. PMID   21371789.
  16. Paiardini A, Fiascarelli A, Rinaldo S, Daidone F, Giardina G, Koes DR, et al. (March 2015). "Screening and in vitro testing of antifolate inhibitors of human cytosolic serine hydroxymethyltransferase". ChemMedChem. 10 (3): 490–497. doi:10.1002/cmdc.201500028. PMC   5438088 . PMID   25677305.
  17. Pinthong C, Maenpuen S, Amornwatcharapong W, Yuthavong Y, Leartsakulpanich U, Chaiyen P (June 2014). "Distinct biochemical properties of human serine hydroxymethyltransferase compared with the Plasmodium enzyme: implications for selective inhibition". The FEBS Journal. 281 (11): 2570–2583. doi: 10.1111/febs.12803 . PMID   24698160.
  18. Witschel MC, Rottmann M, Schwab A, Leartsakulpanich U, Chitnumsub P, Seet M, et al. (April 2015). "Inhibitors of plasmodial serine hydroxymethyltransferase (SHMT): cocrystal structures of pyrazolopyrans with potent blood- and liver-stage activities". Journal of Medicinal Chemistry. 58 (7): 3117–3130. doi:10.1021/jm501987h. PMID   25785478.
  19. Besson V, Nauburger M, Rebeille F, Douce R (1995). "Evidence for three serine hydroxymethyltransferases in green leaf cells. Purification and characterization of the mitochondrial and chloroplastic isoforms". Plant Physiol. Biochem. 33 (6): 665–673.
  20. Martinez-Carrion M, Critz W, Quashnock J (April 1972). "Molecular weight and subunits of serine transhydroxymethylase". Biochemistry. 11 (9): 1613–1615. doi:10.1021/bi00759a011. PMID   5028104.
  21. 1 2 3 Elsea SH, Juyal RC, Jiralerspong S, Finucane BM, Pandolfo M, Greenberg F, et al. (December 1995). "Haploinsufficiency of cytosolic serine hydroxymethyltransferase in the Smith-Magenis syndrome". American Journal of Human Genetics. 57 (6): 1342–1350. PMC   1801426 . PMID   8533763.
  22. Nonaka H, Nakanishi Y, Kuno S, Ota T, Mochidome K, Saito Y, et al. (February 2019). "Design strategy for serine hydroxymethyltransferase probes based on retro-aldol-type reaction". Nature Communications. 10 (1): 876. doi:10.1038/s41467-019-08833-7. PMC   6382819 . PMID   30787298.

Further reading