Maklashina Elena, Cecchini Gary, Dikanov Sergei A
Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158, USA.
Biochim Biophys Acta. 2013 May;1827(5):668-78. doi: 10.1016/j.bbabio.2013.01.010. Epub 2013 Feb 8.
There are two homologous membrane-bound enzymes in Escherichia coli that catalyze reversible conversion between succinate/fumarate and quinone/quinol. Succinate:ubiquinone reductase (SQR) is a component of aerobic respiratory chains, whereas quinol:fumarate reductase (QFR) utilizes menaquinol to reduce fumarate in a final step of anaerobic respiration. Although, both protein complexes are capable of supporting bacterial growth on either minimal succinate or fumarate media, the enzymes are more proficient in their physiological directions. Here we evaluate factors that may underlie this catalytic bias. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.
大肠杆菌中有两种同源的膜结合酶，它们催化琥珀酸/延胡索酸与醌/氢醌之间的可逆转化。琥珀酸：泛醌还原酶（SQR）是有氧呼吸链的一个组成部分，而氢醌：延胡索酸还原酶（QFR）在无氧呼吸的最后一步利用甲基萘醌还原延胡索酸。虽然这两种蛋白质复合物都能够支持细菌在最低限度的琥珀酸或延胡索酸培养基上生长，但这些酶在其生理方向上表现得更为出色。在这里，我们评估了可能导致这种催化偏向的因素。本文是名为“呼吸复合物II：在细胞生理学和疾病中的作用”的特刊的一部分。
