title: Up-regulation of yggG promotes the survival of Escherichia coli cells containing Era-1 mutant protein.
abstract: Era is a highly conserved GTPase essential for bacterial growth. Using a digoxigenin-labeled Era protein to screen a phage expression library of Escherichia coli genomic DNA, yggG, a gene that encodes a putative zinc metalloprotease was isolated and characterized. The deduced amino acid sequence of YggG showed high degrees of similarity to some reported heat shock proteins. In this study, the direct interaction between Era and YggG was confirmed, and it was found that the yggG gene, encoding a 25 kDa heat shock protein, was up-regulated at the mRNA level in partially defective Era GTPase mutants (era-1) and in E. coli cells overproducing Era-1. The delta yggG strain displayed the same growth rate as wild-type strain under normal growth conditions and after heat shock. Overexpression of Era-1 in the delta yggG strain resulted in a stronger growth-inhibitory effect than that in the wild-type strain, while coexpression of YggG partially restored the bacterial growth rate. The results indicated that YggG expression is significantly increased in response to stress caused by the Era-1 mutant protein in E. coli, thus promoting the growth of E. coli.
authors.affiliation: Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Dong
authors.forename: XiaoNan
authors.initials: X
authors.lastname: Zhang
authors.forename: LiChao
authors.initials: L
authors.lastname: Hou
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: NanChun
authors.initials: N
authors.lastname: Chen
authors.forename: SuMin
authors.initials: S
authors.lastname: Chen
mesh_terms: D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D045726:Metalloproteases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D045726:Metalloproteases; C525153:YggG protein, E coli; D019204:GTP-Binding Proteins