J Integr Plant Biol. ›› 2002, Vol. 44 ›› Issue (3): 297-300.

• Research Articles • Previous Articles     Next Articles

Purification and Characterization of Cr-containing Nitrogenase Component I

HUANG Ju Fu, DONG Zhi Gang, ZHANG Hua Feng*, Lü Yu Bing, ZHAO Ying, WANG Zhi Ping   

Abstract:

A mutant UW3, which is unable to fix N2 in the presence of Mo (Nif-) but can undergo phenotypic reversal to Nif+ under Mo deficient conditions, was able to grow in Cr containing but Mo and NH3 deficient medium. A partly purified nitrogenase component Ⅰ protein obtained from UW3 grown on the Cr containing medium was shown to contain Fe and Cr (atom ratio of Fe to Cr and Mo to Cr: 11.60 and 0.41) and to have 70% of the C2H2 and H+ reduction activity of MoFe protein from the wild type strain of Azotobacter vinelandii Lipmann. The Cr containing protein was different in subunit composition from that of MnFe protein purified from the mutant strain grown in the presence of Mn, but similar to that of MoFe protein, that is, it was a tetramer composed of two differentsubunits (α2β2). The preliminary results indicated that the Cr containing protein might be a nitrogenase component Ⅰ protein.

含铬固氮酶组分Ⅰ蛋白的纯化和特性

黄巨富  董志刚  张华峰*  吕玉兵  赵颖  汪志平

(中国科学院植物研究所,北京,100093)

摘要:在含Mo固氮培养基中不能生长而在无Mo条件下可固氮生长的固氮菌(Azotobacter vinelandii Lipmann)突变种UW3, 能在无Mo而含Cr的无氮培养基中生长.从菌体中分离得到的部分纯固氮酶组分Ⅰ蛋白含有CrFe 原子(Fe/Mo/Cr11.600.411.00),并能表达相当于棕色固氮菌野生型固氮菌MoFe蛋白对乙炔和质子还原的70%的活性.与从Mn中生长的UW3菌体中所提取纯化的MnFe蛋白不同,这种含铬蛋白与MoFe蛋白(α2β2)一样,是由两种亚基组成的四聚体.初步结果表明,这种含Cr蛋白可能是一种固氮酶组分Ⅰ蛋白.

关键词 固氮酶 含铬蛋白 突变种UW3 

 

Key words: nitrogenase, Cr containing protein, mutant

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2021 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
备案号:京ICP备16067583号-22