PMID:21597182
| Citation |
Yoneyama, H, Hori, H, Lim, SJ, Murata, T, Ando, T, Isogai, E and Katsumata, R (2011) Isolation of a mutant auxotrophic for L-alanine and identification of three major aminotransferases that synthesize L-alanine in Escherichia coli. Biosci. Biotechnol. Biochem. 75:930-8 |
|---|---|
| Abstract |
For Escherichia coli, it has been assumed that L-alanine is synthesized by alanine-valine transaminase (AvtA) in conjunction with an unknown alanine aminotransferase(s). We isolated alanine auxotrophs from a prototrophic double mutant deficient in AvtA and YfbQ, a novel alanine aminotransferase, by chemical mutagenesis. A shotgun cloning experiment identified two genes, uncharacterized yfdZ and serC, that complemented the alanine auxotrophy. When the yfdZ- or serC-mutation was introduced into the double mutant, one triple mutant (avtA yfbQ yfdZ) showed alanine auxotrophy, and another (avtA yfbQ serC), prototrophy. In addition, we found that four independent alanine auxotrophs possessed a point mutation in yfdZ but not in serC. We also found that yfdZ expression was induced in minimal medium. Furthermore, yfbQ-bearing plasmid conferred the ability to excrete alanine on the mutant lacking D-amino acid dehydrogenase-encoding gene, dadA. From these results, we concluded that E. coli synthesizes L-alanine by means of three aminotransferases, YfbQ, YfdZ, and AvtA. |
| Links | |
| Keywords |
Alanine/biosynthesis; Alanine Transaminase/genetics; Alanine Transaminase/metabolism; Culture Media/metabolism; Escherichia coli/enzymology; Escherichia coli/genetics; Escherichia coli/isolation & purification; Escherichia coli/metabolism; Gene Expression Regulation, Bacterial; Mutagenesis; Mutation; Phenotype |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
See also
References
See Help:References for how to manage references in EcoliWiki.