Genetic code mutations: the breaking of a three billion year invariance.
The genetic code has been unchanging for some three billion years in its canonical ensemble of encoded amino acids, as indicated by the universal adoption of this ensemble by all known organisms. Code mutations beginning with the encoding of 4-fluoro-Trp by Bacillus subtilis, initially replacing and eventually displacing Trp from the ensemble, first revealed the intrinsic mutability of the code. This has since been confirmed by a spectrum of other experimental code alterations in both prokaryotes and eukaryotes. To shed light on the experimental conversion of a rigidly invariant code to a mutating code, the present study examined code mutations determining the propagation of Bacillus subtilis on Trp and 4-, 5- and 6-fluoro-tryptophans. The results obtained with the mutants with respect to cross-inhibitions between the different indole amino acids, and the growth effects of individual nutrient withdrawals rendering essential their biosynthetic pathways, suggested that oligogenic barriers comprising sensitive proteins which malfunction with amino acid analogues provide effective mechanisms for preserving the invariance of the code through immemorial time, and mutations of these barriers open up the code to continuous change.
Mat
Wai-Kin
WK
Department of Biochemistry, Hong Kong University of Science and Technology, Applied Genomics Center, Fok Ying Tung Graduate School, Hong Kong, China.
Xue
Hong
H
Wong
J Tze-Fei
JT
D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics; D003470:Culture Media / Q000737:chemistry; D005815:Genetic Code / Q000235:genetics*; D009154:Mutation; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology
D001426:Bacterial Proteins; D003470:Culture Media; D014364:Tryptophan
Proc Natl Acad Sci U S A. 1976 Jul;73(7):2336-40
1065883
Science. 2010 Jul 2;329(5987):52-6
20488990
Anal Biochem. 1974 Jul;60(1):45-50
4368334
Biochemistry. 2002 Aug 27;41(34):10635-45
12186549
Orig Life Evol Biosph. 2007 Oct;37(4-5):403-8
17611816
Trends Ecol Evol. 2004 Feb;19(2):69-75
16701231
Nucleic Acids Res. 2002 Nov 1;30(21):4692-9
12409460
Can J Biochem. 1980 Mar;58(3):213-8
6989454
J Am Chem Soc. 2003 Jan 29;125(4):935-9
12537491
Proc Natl Acad Sci U S A. 1983 Oct;80(20):6303-6
6413975
Nucleic Acids Res. 2004 Dec 01;32(21):6200-11
15576346
J Am Chem Soc. 2009 Sep 16;131(36):12921-3
19702307
BMC Evol Biol. 2003 Dec 10;3:24
14667253
Nucleic Acids Res. 2003 Dec 1;31(23):6700-9
14627803
Bioessays. 2005 Apr;27(4):416-25
15770677
J Mol Biol. 1993 May 20;231(2):161-6
8389880
J Bacteriol. 2001 Sep;183(18):5414-25
11514527
Science. 2001 Apr 20;292(5516):501-4
11313495
Methods Mol Biol. 2007;352:23-34
17041257
Proc Natl Acad Sci U S A. 1975 May;72(5):1909-12
1057181
Nat Protoc. 2007;2(10):2590-600
17948002
Biochem J. 1988 Jan 1;249(1):305-8
3124823
Science. 2001 Apr 20;292(5516):453-4
11330299
Proc Natl Acad Sci U S A. 2004 Jun 8;101(23):8593-7
15163798