文章基本信息

标题：Membrane association of proline dehydrogenase in Escherichia coli is redox dependent
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作者：J M Wood
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1987
卷号：84
期号：2
页码：373-377
DOI：10.1073/pnas.84.2.373
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The PutA protein, product of the Escherichia coli gene putA, has two functions essential for proline utilization and for the regulation of putP and putA expression: as the peripheral membrane flavoprotein, proline dehydrogenase (EC 1.5.99.8 ), it transfers electrons from proline to the respiratory chain, and, as a repressor, it controls expression of genes putP and putA in response to proline supply. Association of proline dehydrogenase with the membrane was shown to require the simultaneous presence of the soluble enzyme, membranes, and proline. The kinetics of that association, monitored by following proline oxidation in a coupled enzyme assay system, were not altered when the transmembrane proton gradient generated during proline oxidation was dissipated by a proton ionophore. However, D-lactate or NADH could replace proline as a promoter of proline dehydrogenase-membrane association under anaerobic reaction conditions. These data imply that reduction of proline dehydrogenase and/or a membrane constituent promotes enzyme-membrane association. A biochemical mechanism is suggested whereby the concentration of proline dehydrogenase associated with the respiratory chain would be determined by proline supply.