tailieunhanh - Báo cáo Y học: Systematic search for zinc-binding proteins in Escherichia coli

A systematic search for Escherichia coli proteins with the zinc-binding activity was performed using the assay of radioactive Zn(II) binding to total E. coli proteins fractionated by two methods of two-dimensional gel electrophoresis. A total of 30–40 radioactive spots were identified, of which 14 have been assigned from N-terminal sequencing. In addition to five known zinc-binding proteins, nine zincbinding proteins were newly identified including: acetate kinase (AckA), DnaK, serine hydroxymethyltransferase (GlyA), transketolase isozymes (TktA/TktB), translation elongation factor Ts (Tsf), ribosomal proteins L2 (RplB), . | Eur. J. Biochem. 269 2403-2413 2002 FEBS 2002 doi Systematic search for zinc-binding proteins in Escherichia coli Akira Katayama1 2 Atsuko Tsujii2 Akira Wada3 Takeshi Nishino2 and Akira Ishihama 1National Institute of Genetics Department of Molecular Genetics Mishima Shizuoka Japan 2Nippon Medical School Department of Biochemistry and Molecular Biology Bunkyo-ku Tokyo Japan Osaka Medical School Department of Physics Takatsuki Osaka Japan A systematic search for Escherichia coli proteins with the zinc-binding activity was performed using the assay of radioactive Zn II binding to total E. coli proteins fractionated by two methods of two-dimensional gel electrophoresis. A total of 30-40 radioactive spots were identified of which 14 have been assigned from N-terminal sequencing. In addition to five known zinc-binding proteins nine zinc-binding proteins were newly identified including acetate kinase AckA DnaK serine hydroxymethyltransferase GlyA transketolase isozymes TktA TktB translation elongation factor Ts Tsf ribosomal proteins L2 RplB L13 RplM and one of S15 RpsO S16 RpsP or S17 RpsQ . Together with aboLit 00 known inc-binding proteins the total number of zinc-binding proteins in E. coli increased up to more than 30 species or more than 3 of about 1000 proteins expressed under laboratory culture conditions . The speciíìcíty and aflnmty ol zmc-bmdmg eere analysed for some of the zinc-binding proteins. Keywords zinc-binding protein Escherichia coli proteome two-dimensional gel electrophoresis. Zinc is an essential trace element but virtually nontoxic in contrast to iron copper and mercury. Over 300 enzymes or proteins have been identified that require zinc for function 1 2 . l lhyt ícal ami chmcúcal propel iias of hic. such as íss stable association with proteins and its co-ordination flexibility make it highly adaptable to meeting the needs of proteins and enzymes that carry out diverse biological functions 3 . In inc-oont ining enz