非洲脱硫弧菌铁氧化还原蛋白III突变体中[3铁-4硫](1+)簇的缓慢形成

Slow formation of [3Fe-4S](1+) clusters in mutant forms of Desulfovibrio africanus ferredoxin III.

作者信息

Hannan J P, Busch J L, James R, Thomson A J, Moore G R, Davy S L

机构信息

School of Chemical Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.

出版信息

FEBS Lett. 2000 Feb 25;468(2-3):161-5. doi: 10.1016/s0014-5793(00)01210-2.

DOI:10.1016/s0014-5793(00)01210-2

PMID:10692579

Abstract

Desulfovibrio africanus ferredoxin III (Da FdIII) readily interconverts between a 7Fe and an 8Fe form with Asp-14 believed to provide a cluster ligand in the latter form. To investigate the factors important for cluster interconversion in Fe/S cluster-containing proteins we have studied two variants of Da FdIII produced by site-directed mutagenesis, Asp14Glu and Asp14His, with cluster incorporation performed in vitro. Characterisation of these proteins by UV/visible, EPR and (1)H NMR spectroscopies revealed that the formation of the stable 7Fe form of these proteins takes some time to occur. Evidence is presented which indicates the 4Fe-4S cluster is incorporated prior to the 3Fe-4S cluster.

摘要

非洲脱硫弧菌铁氧化还原蛋白III（Da FdIII）能在7Fe形式和8Fe形式之间轻松相互转换，据信天冬氨酸-14在后者形式中为簇提供配体。为了研究对含Fe/S簇蛋白中簇相互转换重要的因素，我们研究了通过定点诱变产生的Da FdIII的两个变体，天冬氨酸14谷氨酸和天冬氨酸14组氨酸，并在体外进行了簇掺入。通过紫外/可见光谱、电子顺磁共振光谱和（1）H核磁共振光谱对这些蛋白质进行表征，结果表明这些蛋白质稳定的7Fe形式的形成需要一些时间。有证据表明4Fe-4S簇在3Fe-4S簇之前掺入。