The C-terminus is the end of an amino acid chain, terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus.
Methyltransferases are a large group of enzymes that all methylate their substrates but can be split into several subclasses based on their structural features. The most common class of methyltransferases is class I, all of which contain a Rossmann fold for binding S-Adenosyl methionine (SAM). Class II methyltransferases contain a SET domain, which are exemplified by SET domain histone methyltransferases, and class III methyltransferases, which are membrane associated. Methyltransferases can also be grouped as different types utilizing different substrates in methyl transfer reactions. These types include protein methyltransferases, DNA/RNA methyltransferases, natural product methyltransferases, and non-SAM dependent methyltransferases. SAM is the classical methyl donor for methyltransferases, however, examples of other methyl donors are seen in nature. The general mechanism for methyl transfer is a SN2-like nucleophilic attack where the methionine sulfur serves as the leaving group and the methyl group attached to it acts as the electrophile that transfers the methyl group to the enzyme substrate. SAM is converted to S-Adenosyl homocysteine (SAH) during this process. The breaking of the SAM-methyl bond and the formation of the substrate-methyl bond happen nearly simultaneously. These enzymatic reactions are found in many pathways and are implicated in genetic diseases, cancer, and metabolic diseases. Another type of methyl transfer is the radical S-Adenosyl methionine (SAM) which is the methylation of unactivated carbon atoms in primary metabolites, proteins, lipids, and RNA.
Protein L-isoaspartyl methyltransferase , also called S-adenosyl-L-methionine:protein-L-isoaspartate O-methyltransferase, is an enzyme which recognizes and catalyzes the repair of damaged L-isoaspartyl and D-aspartyl groups in proteins. It is a highly conserved enzyme which is present in nearly all eukaryotes, archaebacteria, and Gram-negative eubacteria.
In enzymology, a glycine N-methyltransferase is an enzyme that catalyzes the chemical reaction
Guanidinoacetate N-methyltransferase is an enzyme that catalyzes the chemical reaction and is encoded by gene GAMT located on chromosome 19p13.3.
In enzymology, a jasmonate O-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a loganate O-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a protein-glutamate O-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a protein-histidine N-methyltransferase is an enzyme that catalyzes the chemical reaction
The isoprenylcysteine o-methyltransferase carries out carboxyl methylation of cleaved eukaryotic proteins that terminate in a CaaX motif. In Saccharomyces cerevisiae this methylation is carried out by Ste14p, an integral endoplasmic reticulum membrane protein. Ste14p is the founding member of the isoprenylcysteine carboxyl methyltransferase (ICMT) family, whose members share significant sequence homology.
In enzymology, a [ribulose-bisphosphate carboxylase]-lysine N-methyltransferase (EC 2.1.1.127) is an enzyme that catalyzes the chemical reaction
Serine/threonine-protein phosphatase 2A catalytic subunit beta isoform is an enzyme that in humans is encoded by the PPP2CB gene.
Protein-L-isoaspartate(D-aspartate) O-methyltransferase is an enzyme that in humans is encoded by the PCMT1 gene.
Leucine carboxyl methyltransferase 2 is an enzyme that in humans is encoded by the LCMT2 gene.
Steven G. Clarke, an American biochemist, is a director of the UCLA Molecular Biology Institute, a professor of chemistry and biochemistry at UCLA biochemistry department. Clarke heads a laboratory at UCLA's department of chemistry and biochemistry. Clarke is famous for his work on molecular damage and discoveries of novel molecular repair mechanisms.
Leucine carboxyl methyltransferase 1 is an enzyme that in humans is encoded by the LCMT1 gene.
Protein N-terminal methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:N-terminal-(A,P,S)PK-(protein) methyltransferase. This enzyme catalyses the following chemical reaction
[Fructose-bisphosphate aldolase]-lysine N-methyltransferase (EC 2.1.1.259) is an enzyme that catalyses the following chemical reaction
Protein methylation is a type of post-translational modification featuring the addition of methyl groups to proteins. It can occur on the nitrogen-containing side-chains of arginine and lysine, but also at the amino- and carboxy-termini of a number of different proteins. In biology, methyltransferases catalyze the methylation process, activated primarily by S-adenosylmethionine. Protein methylation has been most studied in histones, where the transfer of methyl groups from S-adenosyl methionine is catalyzed by histone methyltransferases. Histones that are methylated on certain residues can act epigenetically to repress or activate gene expression.
