Conservation of residues involved in sugar/H(+) symport by the sucrose permease of Escherichia coli relative to lactose permease.
Building a three-dimensional model of the sucrose permease of Escherichia coli (CscB) with the X-ray crystal structure lactose permease (LacY) as template reveals a similar overall fold for CscB. Moreover, despite only 28% sequence identity and a marked difference in substrate specificity, the structural organization of the residues involved in sugar-binding and H(+) translocation is conserved in CscB. Functional analyses of mutants in the homologous key residues provide strong evidence that they play a similar critical role in the mechanisms of CscB and LacY.
Vadyvaloo
Viveka
V
Department of Physiology and Microbiology, Immunology and Molecular Genetics, Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095-7327, USA.
Smirnova
Irina N
IN
Kasho
Vladimir N
VN
Kaback
H Ronald
HR
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D050260:Carbohydrate Metabolism; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D006859:Hydrogen / Q000378:metabolism; D007700:Kinetics; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009004:Monosaccharide Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D027981:Symporters / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D029968:Escherichia coli Proteins; C050221:LacY protein, E coli; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D011994:Recombinant Proteins; D027981:Symporters; C056379:cscB protein, E coli; D006859:Hydrogen