CRYSTAL-STRUCTURE OF DESULFOREDOXIN FROM DESULFOVIBRIO-GIGAS DETERMINED AT 1.8 ANGSTROM RESOLUTION - A NOVEL NONHEME IRON PROTEIN-STRUCTURE
CRYSTAL-STRUCTURE OF DESULFOREDOXIN FROM DESULFOVIBRIO-GIGAS DETERMINED AT 1.8 ANGSTROM RESOLUTION - A NOVEL NONHEME IRON PROTEIN-STRUCTURE
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DOI：
10.1006/jmbi.1995.0465
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发表时间：
1995-09-01
影响因子：
5.6
通讯作者：
ROMAO, MJ
中科院分区：
文献类型：
--
作者：
ARCHER, M;HUBER, R;ROMAO, MJ
以铟取代蛋白为单衍生物，用SIRAS方法解析了一种新的同源二聚体(2×36个氨基酸)非血红素铁蛋白--长硫弧菌脱氧还蛋白的晶体结构。在1.8埃分辨率下，结构被细化到16.9%的结晶学X因子。从聚乙二醇4K和硫酸锂中生长了天然的去氧还蛋白晶体，晶胞常数a=b=42.18埃，=72.22埃(对于由聚乙二醇4K生长的晶体)，它们属于P3(2)21空间群。被铟取代的蛋白质在相同的条件下同构结晶。2重对称二聚体是牢固的氢键，折叠为一个不完整的β-桶，两个铁中心放置在分子的相反极性上。每个铁原子以扭曲的四面体排列与四个半胱氨基残基配位。两个铁原子相距16埃，但通过沿多肽链的14个共价键和两个氢键连接在2倍轴上。去硫还蛋白和去氧还蛋白具有一些结构特征，但在金属环境和水结构方面表现出显著的差异，这是已知的去氧还蛋白和去氧还蛋白光谱差异的原因。(C)1995年学术出版社有限公司
The crystal structure of desulforedoxin from Desulfovibrio gigas, a new homo-dimeric (2x36 amino acids) non-heme iron protein, has been solved by the SIRAS method using the indium-substituted protein as the single derivative. The structure was refined to a crystallographic X-factor of 16.9% at 1.8 Angstrom resolution. Native desulforedoxin crystals were grown from either PEG 4K or lithium sulfate, with cell constants a = b = 42.18 Angstrom, = 72.22 Angstrom (for crystals grown from PEG 4K), and they belong to space group P3(2)21. The indium-substituted protein crystallized isomorphously under the same conditions.The 2-fold symmetric dimer is firmly hydrogen bonded and folds as an incomplete beta-barrel with the two iron centers placed on opposite poles of the molecule. Each iron atom is coordinated to four cysteinyl residues in a distorted tetrahedral arrangement. Both iron atoms are 16 Angstrom apart but connected across the 2-fold axis by 14 covalent bonds along the polypeptide chain plus two hydrogen bonds.Desulforedoxin and rubredoxin share some structural features but show significant differences in terms of metal environment and water structure, which account for the known spectroscopic differences between rubredoxin and desulforedoxin. (C) 1995 Academic Press Limited