Disease relevance of glyV

• In Pseudomonas sp. strain B13, a circular form of the clc element, which carries an 18-bp DNA sequence identical to the 3'-end portion of glyV as part of its attachment site (attP), could be detected [1].
• Two transversion-specific mutator loci, mutA and mutC, were identified in Escherichia coli [2].
• Here, we demonstrate that mutA cells express an error-prone DNA polymerase by using an in vitro experimental system based on the conversion of phage M13 single-stranded viral DNA bearing a model mutagenic lesion to the double-stranded replicative form [3].

High impact information on glyV

• The ins and outs of GroEL-mediated protein folding [4].
• Mutator tRNAs are encoded by the Escherichia coli mutator genes mutA and mutC: a novel pathway for mutagenesis [5].
• Both its mutagenic specificity and complementation experiments confirmed that mutA is distinct from mutL and from a nearby mutator locus, miaA [2].
• The specificity of reversion of lacZ mutations in a mutC strain is identical to that in a mutA strain [2].
• The phenotype of a mutA mutL double mutator strain suggests that the mutA gene product prevents some replication errors [2].

Chemical compound and disease context of glyV

• Escherichia coli cells expressing a mutant glyV (glycine tRNA) gene have a UVM-constitutive phenotype: implications for mechanisms underlying the mutA or mutC mutator effect [6].
• Translational stress-induced mutagenesis (TSM) refers to the elevated mutagenesis observed in Escherichia coli cells in which mistranslation has been increased as a result of mutations in tRNA genes (such as mutA) or by exposure to streptomycin [7].

Biological context of glyV

• Upon chromosomal integration of the clc element into a bacterial attachment site (attB), a functional glyV was reconstructed at the right end of the element [1].
• The element integrates site and orientation specifically into the chromosomes of various bacterial recipients, with a glycine tRNA structural gene (glyV) as the integration site [1].
• Neither overexpression of the lexA gene through a multicopy plasmid nor replacement of the wild-type lexA allele with the lexA1[Ind-] allele interferes with the expression of the mutA phenotype [8].
• Escherichia coli cells bearing mutA, a mutant glyV tRNA gene, express a recA-dependent error-prone DNA replication activity [3].
• Thus, the recBCD-dependent homologous recombination system is a component of the signal pathway that activates an error-prone DNA polymerase in mutA cells [9].

Associations of glyV with chemical compounds

• By purifying DNA polymerase III* from TSM-induced and control cells, and by testing its fidelity on templates bearing 3,N(4)-ethenocytosine (a mutagenic DNA lesion), as well as on undamaged DNA templates, we show here that polymerase III* purified from mutA cells is error-prone as compared with that from control cells [7].
• The mutA allele differs from the wild type glyV gene by a base substitution in the anticodon such that the resulting tRNA misreads certain aspartate codons as glycine, resulting in random, low-level Asp-->Gly substitutions in proteins [10].

Other interactions of glyV

• The mutA locus maps very near to, but is separable from, mutL, at about 95 min on the E. coli chromosome [2].
• Finally, we show that the mutA phenotype is abolished in cells deficient for recB, suggesting that cellular recombination functions may be required for the expression of the mutator phenotype [8].
• Also, the behavior of a mutC mutS double mutant is identical to that of a mutA mutL double mutant [2].
• Our results also indicate that mutA deltarecA double mutants display a normal UVM phenotype, suggesting that the mutA effect is recA dependent [6].
• The mutA phenotype does not require lexA-regulated SOS mutagenesis functions, and appears to be suppressed in cells defective for RecABC-dependent homologous recombination functions [11].

References