title: Multiple isoelectric forms of bacterial penicillin-binding proteins: artefacts or genuine cellular components?
abstract: Some bacterial penicillin-binding proteins (PBPs) are reported to exist as multiple isoelectric forms. Other PBPs were examined by two-dimensional electrophoresis to establish whether multiple isoelectric forms are widespread amongst PBPs. Bacillus subtilis PBPs 3 and 5 and Escherichia coli PBPs 1b alpha and 1b gamma focussed as discrete spots with no evidence of multiple isoforms. However, E. coli PBPs 1b beta and 4 displayed isoelectric variants. The results are discussed in relation to current models of bacterial peptidoglycan structure.
mesh_terms: D001412:Bacillus subtilis / Q000032:analysis / Q000235:genetics; D001426:Bacterial Proteins / Q000032:analysis*; D002352:Carrier Proteins / Q000032:analysis*; D002462:Cell Membrane; D015180:Electrophoresis, Gel, Two-Dimensional; D004926:Escherichia coli / Q000032:analysis / Q000235:genetics; D006602:Hexosyltransferases; D007525:Isoelectric Focusing; D002267:Muramoylpentapeptide Carboxypeptidase / Q000032:analysis*; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism*; D010458:Peptidyl Transferases; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase