Netter P, Robineau S, Sirand-Pugnet P, Fauvarque M O
Centre de Génétique Moléculaire, Laboratoire Propre du C.N.R.S. Associé à l'Université Pierre et Marie Curie, Gif sur Yvette, France.
Curr Genet. 1992 Feb;21(2):147-51. doi: 10.1007/BF00318474.
We have analyzed a mutation in the mitochondrial gene oxi3 coding for subunit I of cytochrome-oxidase in the yeast Saccharomyces cerevisiae. This mutation replaces one of the seven invariant histidines of the polypeptide (position 378) by a tyrosine, and leads to a respiratory deficient phenotype. A total of 157 revertants, which have recovered the ability to grow on a respiratory substrate, have been selected from this mutant (tyrosine 378). The nature of the reversion has been analysed by a rapid screening procedure and 32 of the revertants have been sequenced. They are all true back-mutations reintroducing the histidine in position 378. This very exceptional situation suggests that this histidine is a ligand of the redox center of cytochrome oxidase.
我们分析了酵母酿酒酵母中线粒体基因oxi3的一个突变，该基因编码细胞色素氧化酶的亚基I。此突变使多肽的七个不变组氨酸之一（第378位）被酪氨酸取代，并导致呼吸缺陷表型。已从该突变体（酪氨酸378）中筛选出总共157个回复突变体，它们恢复了在呼吸底物上生长的能力。通过快速筛选程序分析了回复突变的性质，并对其中32个回复突变体进行了测序。它们都是真正的反向突变，重新引入了第378位的组氨酸。这种非常特殊的情况表明，这个组氨酸是细胞色素氧化酶氧化还原中心的一个配体。
