Wakagi T, Fujii T, Oshima T
Department of Life Science, Tokyo Institute of Technology, Yokahama, Japan.
Biochem Biophys Res Commun. 1996 Aug 14;225(2):489-93. doi: 10.1006/bbrc.1996.1200.
The gene encoding a novel zinc-containing ferredoxin from a hyperthermophilic and acidophilic archaeon (archaebacterium) Sulfolobus sp. strain 7 was cloned and sequenced. The DNA sequence predicts a 103 residue protein after removal of N-terminal methionine, which is in good agreement with the results of the protein analysis. Surprisingly, the residues responsible for binding a zinc atom were conserved among three other thermoacidophilic archaea. A common sequence stretch VXGXHXGHX8-17PXXLGXHGTX38-56KXDPV is proposed as a new zinc-binding motif, where three histidines and an aspartic acid are ligated to a zinc atom. The ferredoxin gene was expressed in Eschericia coli. The recombinant ferredoxin was indistinguishable from the protein purified from Sulfolobus sp. strain 7 cells by several criteria so far investigated except that the methylation of the 29th lysine was suppressed.
编码来自嗜热嗜酸古菌（古细菌）硫化叶菌属菌株7的一种新型含锌铁氧还蛋白的基因被克隆并测序。DNA序列预测去除N端甲硫氨酸后会产生一个103个残基的蛋白质，这与蛋白质分析结果高度一致。令人惊讶的是，负责结合锌原子的残基在其他三种嗜热嗜酸古菌中是保守的。一个共同的序列片段VXGXHXGHX8 - 17PXXLGXHGTX38 - 56KXDPV被提议作为一种新的锌结合基序，其中三个组氨酸和一个天冬氨酸与一个锌原子相连。铁氧还蛋白基因在大肠杆菌中表达。到目前为止，通过几个标准研究发现，重组铁氧还蛋白与从硫化叶菌属菌株7细胞中纯化的蛋白质没有区别，只是第29位赖氨酸的甲基化受到了抑制。
