Bacterial, archaeal and plant plastid code

Last updated

The bacterial, archaeal and plant plastid code (translation table 11) is the DNA code used by bacteria, archaea, prokaryotic viruses and chloroplast proteins. It is essentially the same as the standard code, however there are some variations in alternative start codons.

Contents

The code

Amino-acid biochemical propertiesNonpolarPolarBasicAcidicTermination: stop codon
Standard genetic code
1st
base
2nd base3rd
base
UCAG
UUUU(Phe/F) Phenylalanine UCU(Ser/S) Serine UAU(Tyr/Y) Tyrosine UGU(Cys/C) Cysteine U
UUCUCCUACUGCC
UUA(Leu/L) Leucine UCAUAA Stop (Ochre) [B] UGA Stop (Opal) [B] A
UUG [A] UCGUAG Stop (Amber) [B] UGG(Trp/W) Tryptophan G
CCUUCCU(Pro/P) Proline CAU(His/H) Histidine CGU(Arg/R) Arginine U
CUCCCCCACCGCC
CUACCACAA(Gln/Q) Glutamine CGAA
CUG [A] CCGCAGCGGG
AAUU(Ile/I) Isoleucine ACU(Thr/T) Threonine AAU(Asn/N) Asparagine AGU(Ser/S) Serine U
AUCACCAACAGCC
AUAACAAAA(Lys/K) Lysine AGA(Arg/R) Arginine A
AUG [A] (Met/M) Methionine ACGAAGAGGG
GGUU(Val/V) Valine GCU(Ala/A) Alanine GAU(Asp/D) Aspartic acid GGU(Gly/G) Glycine U
GUCGCCGACGGCC
GUAGCAGAA(Glu/E) Glutamic acid GGAA
GUGGCGGAGGGGG
A The codon AUG both codes for methionine and serves as an initiation site: the first AUG in an mRNA's coding region is where translation into protein begins. [1] The other start codons listed by GenBank are rare in eukaryotes and generally codes for Met/fMet. [2]
B ^ ^ ^ The historical basis for designating the stop codons as amber, ochre and opal is described in an autobiography by Sydney Brenner [3] and in a historical article by Bob Edgar. [4]

As in the standard code, initiation is most efficient at AUG. In addition, GUG and UUG starts are documented in archaea and bacteria. [5] [6] [7] [8] [9] [10] [11] In Escherichia coli , UUG is estimated to serve as initiator for about 3% of the bacterium's proteins. [12] CUG is known to function as an initiator for one plasmid-encoded protein (RepA) in E. coli. [13] In addition to the NUG initiations, in rare cases bacteria can initiate translation from an AUU codon as e.g. in the case of poly(A) polymerase PcnB and the InfC gene that codes for translation initiation factor IF3. [14] [15] [9] [16] The internal assignments are the same as in the standard code though UGA codes at low efficiency for tryptophan in Bacillus subtilis and, presumably, in Escherichia coli. [17]

See also

Related Research Articles

<span class="mw-page-title-main">Genetic code</span> Rules by which information encoded within genetic material is translated into proteins

The genetic code is the set of rules used by living cells to translate information encoded within genetic material into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries.

<span class="mw-page-title-main">Stop codon</span> Codon that marks the end of a protein-coding sequence

In molecular biology, a stop codon is a codon that signals the termination of the translation process of the current protein. Most codons in messenger RNA correspond to the addition of an amino acid to a growing polypeptide chain, which may ultimately become a protein; stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain.

<i>Escherichia coli</i> Enteric, rod-shaped, gram-negative bacterium

Escherichia coli ( ESH-ə-RIK-ee-ə KOH-ly) is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes such as EPEC, and ETEC are pathogenic and can cause serious food poisoning in their hosts, and are occasionally responsible for food contamination incidents that prompt product recalls. Most strains are part of the normal microbiota of the gut and are harmless or even beneficial to humans (although these strains tend to be less studied than the pathogenic ones). For example, some strains of E. coli benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by pathogenic bacteria. These mutually beneficial relationships between E. coli and humans are a type of mutualistic biological relationship — where both the humans and the E. coli are benefitting each other. E. coli is expelled into the environment within fecal matter. The bacterium grows massively in fresh fecal matter under aerobic conditions for three days, but its numbers decline slowly afterwards.

<span class="mw-page-title-main">Codon usage bias</span> Genetic bias in coding DNA

Codon usage bias refers to differences in the frequency of occurrence of synonymous codons in coding DNA. A codon is a series of three nucleotides that encodes a specific amino acid residue in a polypeptide chain or for the termination of translation.

<span class="mw-page-title-main">Translation (biology)</span> Cellular process of protein synthesis

In biology, translation is the process in living cells in which proteins are produced using RNA molecules as templates. The generated protein is a sequence of amino acids. This sequence is determined by the sequence of nucleotides in the RNA. The nucleotides are considered three at a time. Each such triple results in addition of one specific amino acid to the protein being generated. The matching from nucleotide triple to amino acid is called the genetic code. The translation is performed by a large complex of functional RNA and proteins called ribosomes. The entire process is called gene expression.

The 5′ untranslated region is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. While called untranslated, the 5′ UTR or a portion of it is sometimes translated into a protein product. This product can then regulate the translation of the main coding sequence of the mRNA. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation.

The Shine–Dalgarno (SD) sequence is a ribosomal binding site in bacterial and archaeal messenger RNA, generally located around 8 bases upstream of the start codon AUG. The RNA sequence helps recruit the ribosome to the messenger RNA (mRNA) to initiate protein synthesis by aligning the ribosome with the start codon. Once recruited, tRNA may add amino acids in sequence as dictated by the codons, moving downstream from the translational start site.

<span class="mw-page-title-main">Start codon</span> First codon of a messenger RNA translated by a ribosome

The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and archaea and a N-formylmethionine (fMet) in bacteria, mitochondria and plastids.

Bacterial translation is the process by which messenger RNA is translated into proteins in bacteria.

Neutral mutations are changes in DNA sequence that are neither beneficial nor detrimental to the ability of an organism to survive and reproduce. In population genetics, mutations in which natural selection does not affect the spread of the mutation in a species are termed neutral mutations. Neutral mutations that are inheritable and not linked to any genes under selection will be lost or will replace all other alleles of the gene. That loss or fixation of the gene proceeds based on random sampling known as genetic drift. A neutral mutation that is in linkage disequilibrium with other alleles that are under selection may proceed to loss or fixation via genetic hitchhiking and/or background selection.

The gene rpoS encodes the sigma factor sigma-38, a 37.8 kD protein in Escherichia coli. Sigma factors are proteins that regulate transcription in bacteria. Sigma factors can be activated in response to different environmental conditions. rpoS is transcribed in late exponential phase, and RpoS is the primary regulator of stationary phase genes. RpoS is a central regulator of the general stress response and operates in both a retroactive and a proactive manner: it not only allows the cell to survive environmental challenges, but it also prepares the cell for subsequent stresses (cross-protection). The transcriptional regulator CsgD is central to biofilm formation, controlling the expression of the curli structural and export proteins, and the diguanylate cyclase, adrA, which indirectly activates cellulose production. The rpoS gene most likely originated in the gammaproteobacteria.

A bacterial initiation factor (IF) is a protein that stabilizes the initiation complex for polypeptide translation.

fis E. coli gene

fis is an E. coli gene encoding the Fis protein. The regulation of this gene is more complex than most other genes in the E. coli genome, as Fis is an important protein which regulates expression of other genes. It is supposed that fis is regulated by H-NS, IHF and CRP. It also regulates its own expression (autoregulation). Fis is one of the most abundant DNA binding proteins in Escherichia coli under nutrient-rich growth conditions.

<span class="mw-page-title-main">EIF1</span> Protein-coding gene in the species Homo sapiens

Eukaryotic translation initiation factor 1 (eIF1) is a protein that in humans is encoded by the EIF1 gene. It is related to yeast SUI1.

In molecular cloning, a vector is any particle used as a vehicle to artificially carry a foreign nucleic sequence – usually DNA – into another cell, where it can be replicated and/or expressed. A vector containing foreign DNA is termed recombinant DNA. The four major types of vectors are plasmids, viral vectors, cosmids, and artificial chromosomes. Of these, the most commonly used vectors are plasmids. Common to all engineered vectors are an origin of replication, a multicloning site, and a selectable marker.

<span class="mw-page-title-main">Toxin-antitoxin system</span> Biological process

A toxin-antitoxin system consists of a "toxin" and a corresponding "antitoxin", usually encoded by closely linked genes. The toxin is usually a protein while the antitoxin can be a protein or an RNA. Toxin-antitoxin systems are widely distributed in prokaryotes, and organisms often have them in multiple copies. When these systems are contained on plasmids – transferable genetic elements – they ensure that only the daughter cells that inherit the plasmid survive after cell division. If the plasmid is absent in a daughter cell, the unstable antitoxin is degraded and the stable toxic protein kills the new cell; this is known as 'post-segregational killing' (PSK).

<span class="mw-page-title-main">DNA and RNA codon tables</span> List of standard rules to translate DNA encoded information into proteins

A codon table can be used to translate a genetic code into a sequence of amino acids. The standard genetic code is traditionally represented as an RNA codon table, because when proteins are made in a cell by ribosomes, it is messenger RNA (mRNA) that directs protein synthesis. The mRNA sequence is determined by the sequence of genomic DNA. In this context, the standard genetic code is referred to as translation table 1. It can also be represented in a DNA codon table. The DNA codons in such tables occur on the sense DNA strand and are arranged in a 5′-to-3′ direction. Different tables with alternate codons are used depending on the source of the genetic code, such as from a cell nucleus, mitochondrion, plastid, or hydrogenosome.

<i>Escherichia coli</i> in molecular biology Gram-negative gammaproteobacterium

Escherichia coli is a Gram-negative gammaproteobacterium commonly found in the lower intestine of warm-blooded organisms (endotherms). The descendants of two isolates, K-12 and B strain, are used routinely in molecular biology as both a tool and a model organism.

Monica Riley was an American scientist who contributed to the discovery of messenger RNA in her Ph.D work with Arthur Pardee, and was later a pioneer in the exploration and computer representation of the Escherichia coli genome.

Julio Collado-Vides is a Guatemalan scientist and Professor of Computational Genomics at the National Autonomous University of Mexico. His research focuses on genomics and bioinformatics.

References

This article incorporates text from the United States National Library of Medicine, which is in the public domain. [18]

  1. Nakamoto T (March 2009). "Evolution and the universality of the mechanism of initiation of protein synthesis". Gene. 432 (1–2): 1–6. doi:10.1016/j.gene.2008.11.001. PMID   19056476.
  2. Blattner, F. R.; Plunkett g, G.; Bloch, C. A.; Perna, N. T.; Burland, V.; Riley, M.; Collado-Vides, J.; Glasner, J. D.; Rode, C. K.; Mayhew, G. F.; Gregor, J.; Davis, N. W.; Kirkpatrick, H. A.; Goeden, M. A.; Rose, D. J.; Mau, B.; Shao, Y. (1997). "The Complete Genome Sequence of Escherichia coli K-12". Science. 277 (5331): 1453–1462. doi:10.1126/science.277.5331.1453. PMID   9278503.
  3. Brenner S. A Life in Science (2001) Published by Biomed Central Limited ISBN   0-9540278-0-9 see pages 101-104
  4. Edgar B (2004). "The genome of bacteriophage T4: an archeological dig". Genetics. 168 (2): 575–82. PMC   1448817 . PMID   15514035. see pages 580-581
  5. Kozak, M (March 1983). "Comparison of initiation of protein synthesis in procaryotes, eucaryotes, and organelles". Microbiological Reviews. 47 (1): 1–45. doi:10.1128/MMBR.47.1.1-45.1983. PMC   281560 . PMID   6343825.
  6. Fotheringham, IG; Dacey, SA; Taylor, PP; Smith, TJ; Hunter, MG; Finlay, ME; Primrose, SB; Parker, DM; Edwards, RM (15 March 1986). "The cloning and sequence analysis of the aspC and tyrB genes from Escherichia coli K12. Comparison of the primary structures of the aspartate aminotransferase and aromatic aminotransferase of E. coli with those of the pig aspartate aminotransferase isoenzymes". The Biochemical Journal. 234 (3): 593–604. doi:10.1042/bj2340593. PMC   1146613 . PMID   3521591.
  7. Golderer, G; Dlaska, M; Gröbner, P; Piendl, W (October 1995). "TTG serves as an initiation codon for the ribosomal protein MvaS7 from the archaeon Methanococcus vannielii". Journal of Bacteriology. 177 (20): 5994–6. doi:10.1128/jb.177.20.5994-5996.1995. PMC   177430 . PMID   7592355.
  8. Nölling, J; Pihl, TD; Vriesema, A; Reeve, JN (May 1995). "Organization and growth phase-dependent transcription of methane genes in two regions of the Methanobacterium thermoautotrophicum genome". Journal of Bacteriology. 177 (9): 2460–8. doi:10.1128/jb.177.9.2460-2468.1995. PMC   176905 . PMID   7730278.
  9. 1 2 Sazuka, T; Ohara, O (31 August 1996). "Sequence features surrounding the translation initiation sites assigned on the genome sequence of Synechocystis sp. strain PCC6803 by amino-terminal protein sequencing". DNA Research. 3 (4): 225–32. doi: 10.1093/dnares/3.4.225 . PMID   8946162.
  10. Genser, KF; Renner, G; Schwab, H (8 October 1998). "Molecular cloning, sequencing and expression in Escherichia coli of the poly(3-hydroxyalkanoate) synthesis genes from Alcaligenes latus DSM1124". Journal of Biotechnology. 64 (2–3): 125–35. doi:10.1016/S0168-1656(98)00093-5. PMID   9821671.
  11. Wang, G; Nie, L; Tan, H (2003). "Cloning and characterization of sanO, a gene involved in nikkomycin biosynthesis in Streptomyces ansochromogenes". Letters in Applied Microbiology. 37 (6): 452–7. doi: 10.1046/j.1472-765x.2003.01426.x . PMID   14633098.
  12. Blattner, FR; Plunkett G, 3rd; Bloch, CA; Perna, NT; Burland, V; Riley, M; Collado-Vides, J; Glasner, JD; Rode, CK; Mayhew, GF; Gregor, J; Davis, NW; Kirkpatrick, HA; Goeden, MA; Rose, DJ; Mau, B; Shao, Y (5 September 1997). "The complete genome sequence of Escherichia coli K-12". Science. 277 (5331): 1453–62. doi:10.1126/science.277.5331.1453. PMID   9278503.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  13. Spiers, AJ; Bergquist, PL (December 1992). "Expression and regulation of the RepA protein of the RepFIB replicon from plasmid P307". Journal of Bacteriology. 174 (23): 7533–41. doi:10.1128/jb.174.23.7533-7541.1992. PMC   207463 . PMID   1447126.
  14. Polard, P; Prère, MF; Chandler, M; Fayet, O (5 December 1991). "Programmed translational frameshifting and initiation at an AUU codon in gene expression of bacterial insertion sequence IS911". Journal of Molecular Biology. 222 (3): 465–77. doi:10.1016/0022-2836(91)90490-w. PMID   1660923.
  15. Liveris, D; Schwartz, JJ; Geertman, R; Schwartz, I (1 September 1993). "Molecular cloning and sequencing of infC, the gene encoding translation initiation factor IF3, from four enterobacterial species". FEMS Microbiology Letters. 112 (2): 211–6. doi: 10.1111/j.1574-6968.1993.tb06450.x . PMID   8405963.
  16. Binns, N; Masters, M (June 2002). "Expression of the Escherichia coli pcnB gene is translationally limited using an inefficient start codon: a second chromosomal example of translation initiated at AUU". Molecular Microbiology. 44 (5): 1287–98. doi: 10.1046/j.1365-2958.2002.02945.x . PMID   12068810.
  17. Hatfield, D; Diamond, A (March 1993). "UGA: a split personality in the universal genetic code". Trends in Genetics. 9 (3): 69–70. doi:10.1016/0168-9525(93)90215-4. PMID   8488562.
  18. Elzanowski A, Ostell J, Leipe D, Soussov V. "The Genetic Codes". Taxonomy browser. National Center for Biotechnology Information (NCBI), U.S. National Library of Medicine. Retrieved 19 March 2016.