Mutagenesis of histidine 26 demonstrates the importance of loop-loop and loop-protein interactions for the function of iso-1-cytochrome c.
Mutagenesis of histidine 26 demonstrates the importance of loop-loop and loop-protein interactions for the function of iso-1-cytochrome c.
复制标题
组氨酸 26 的诱变证明了环-环和环-蛋白质相互作用对于 iso-1-细胞色素 c 功能的重要性。
DOI：
10.1002/pro.5560070417
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Boose,TL
中科院分区：
文献类型：
--
作者：
Fetrow,JS;Dreher,U;Wiland,DJ;Schaak,DL;Boose,TL
In yeast iso‐1‐cytochromec, the side chain of histidine 26 (His26) attaches omega loop A to the main body of the protein by forming a hydrogen bond to the backbone atom carbonyl of glutamic acid 44. The His26 side chain also forms a stabilizing intra‐loop interaction through a hydrogen bond to the backbone amide of asparagine 31. To investigate the importance of loop‐protein attachment and intra‐loop interactions to the structure and function of this protein, a series of site‐directed and random‐directed mutations were produced at His26. Yeast strains expressing these variant proteins were analyzed for their ability to grow on non‐fermentable carbon sources and for their intracellular production of cytochromec. While the data show that mutations at His26 lead toslightly decreased intracellular amounts of cytochromec, the level of cytochromecfunction is decreased more. The data suggest that cytochromecreductase binding is affected more than cytochromecoxidase or lactate dehydrogenase binding. We propose that mutations at this residue increase loop mobility, which, in turn, decreases the protein's ability to bind redox partners.
