title: Her2p molecular modeling, mutant analysis and intramitochondrial localization.
abstract: Bacterial GatCAB amidotransferases are responsible for the transamidation of mischarged glutamyl-tRNA(Gln) into glutaminyl-tRNA(Gln). Mitochondria matrix also has a multienzymatic complex necessary for the transamidation of glutamyl-tRNA(Gln). Gtf1p, Her2p and Pet112p are the constituents of mitochondrial GatFAB amidotransferase complex. Her2p is subunit A of GatFAB complex, while Gtf1p is subunit F, a connector protein between Pet112p (subunit B) and Her2p. Here we evaluate through molecular modeling and amino acid correlation analysis the HER2 protein family. Localization studies indicated that Her2p is predominantly localized in the mitochondrial outer membrane, but it is also located in the mitochondrial matrix where together with Pet112p and Gtf1p constitutes the GatFAB complex. Finally, HER2 random mutagenesis unveiled important residues that provide thermo stability for the complex and are differently suppressed by overexpression of GTF1 or PET112. For instance, her2/ts11 mutant showed its fermentative growth impaired, and poorly rescued by GTF1 indicating that Her2p unknown function in the mitochondria outer membrane affects cell viability.
authors.affiliation: Escola de Artes, Ciências e Humanidades - USP, Brazil.
authors.forename: José Ribamar
authors.initials: JR
authors.lastname: Ferreira-Júnior
authors.forename: Lucas
authors.initials: L
authors.lastname: Bleicher
authors.forename: Mario H
authors.initials: MH
authors.lastname: Barros
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics* / Q000378:metabolism; D002470:Cell Survival; D002874:Chromosome Mapping; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005973:Glutamine / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D019884:Nitrogenous Group Transferases / Q000235:genetics* / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment; D000637:Transaminases / Q000235:genetics* / Q000378:metabolism
chemical_list: D024101:Mitochondrial Proteins; D012346:RNA, Transfer, Amino Acyl; D029701:Saccharomyces cerevisiae Proteins; C483187:glutamyl-tRNA(Gln); D005973:Glutamine; C000589643:Her2 protein, S cerevisiae; D019884:Nitrogenous Group Transferases; D000637:Transaminases; D000604:Amino Acyl-tRNA Synthetases; C567965:glutaminyl transamidase subunit F, S cerevisiae; C108099:PET112 protein, S cerevisiae
keywords: Amidotransferase; GatFAB; Mitochondria translation; PAGE; PCR; PMSF; Phenylmethanesulfonyl fluoride; SDS; glutamyl-tRNAGln; mitochondrial DNA; mtDNA; polyacrylamide gel electrophoresis; polymerase chain reaction; respiratory deficient mutant lacking mitochondrial DNA; respiratory deficient mutant with a partially deleted mitochondrial genome; sodium dodecyl sulfate; temperature sensitive mutant; ts; ρ(o) mutant; ρ(−) mutant