1CXY

STRUCTURE AND CHARACTERIZATION OF ECTOTHIORHODOSPIRA VACUOLATA CYTOCHROME B558, A PROKARYOTIC HOMOLOGUE OF CYTOCHROME B5

1CXY の概要

• エントリーDOI: 10.2210/pdb1cxy/pdb
• 分子名称: CYTOCHROME B5, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: helix, beta-strand, electron transport
• 由来する生物種: Ectothiorhodospira shaposhnikovii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 10722.77

構造登録者

Kostanjevecki, V.,Leys, D.,Van Driessche, G.,Meyer, T.E.,Cusanovich, M.A.,Fischer, U.,Guisez, Y.,Van Beeumen, J. (登録日: 1999-08-31, 公開日: 1999-09-10, 最終更新日: 2024-11-20)

主引用文献

Kostanjevecki, V.,Leys, D.,Van Driessche, G.,Meyer, T.E.,Cusanovich, M.A.,Fischer, U.,Guisez, Y.,Van Beeumen, J.
Structure and characterization of Ectothiorhodospira vacuolata cytochrome b(558), a prokaryotic homologue of cytochrome b(5).
J.Biol.Chem., 274:35614-35620, 1999

PubMed Abstract: A soluble cytochrome b(558) from the purple phototropic bacterium Ectothiorhodospira vacuolata was completely sequenced by a combination of automated Edman degradation and mass spectrometry. The protein, with a measured mass of 10,094.7 Da, contains 90 residues and binds a single protoheme. Unexpectedly, the sequence shows homology to eukaryotic cytochromes b(5). As no prokaryotic homologue had been reported so far, we developed a protocol for the expression, purification, and crystallization of recombinant cytochrome b(558). The structure was solved by molecular replacement to a resolution of 1.65 A. It shows that cytochrome b(558) is indeed the first bacterial cytochrome b(5) to be characterized and differs from its eukaryotic counterparts by the presence of a disulfide bridge and a four-residue insertion in front of the sixth ligand (histidine). Eukaryotes contain a variety of b(5) homologues, including soluble and membrane-bound multifunctional proteins as well as multidomain enzymes such as sulfite oxidase, fatty-acid desaturase, nitrate reductase, and lactate dehydrogenase. A search of the Mycobacterium tuberculosis genome showed that a previously unidentified gene encodes a fatty-acid desaturase with an N-terminal b(5) domain. Thus, it may provide another example of a bacterial b(5) homologue.

PubMed: 10585439
DOI: 10.1074/jbc.274.50.35614

実験手法

X-RAY DIFFRACTION (1.65 Å)