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定义了Flavobacterium johnsoniae中的替代复合物III和细胞氧化酶之间的直接电子转移连接

Katarzyna Lorencik¹, Robert Ekiert¹, Rafał Pietras¹

¹Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.

Biochimica et biophysica acta. Bioenergetics

|February 16, 2025

概括

移动细胞色素c域 (mdA) 对于从细菌替代复合III (ACIII) 到细胞色素a3氧化酶的电子转移至关重要. 这项研究阐明了mDA的关键作用和ACIII中的血红素还原电位安排.

科学领域:

生物化学生化学
微生物学微生物学
分子生物学分子生物学

背景情况:

替代复合III (ACIII) 是电子运输链中的细菌酶,氧化醇并将电子转移到外部受体.
在Flavobacterium johnsoniae中,ACIII的ActA子单元含有移动单血型细胞染色体c域 (mdA),建议将ACIII与细胞染色体aa3氧化酶联系起来.

研究的目的:

研究mda域在ACIII和cytochrome aa3氧化酶之间电子转移中的作用.
为了确定ACIII的mdA和ActE子单元中hemes的氧化还原中点潜力.

主要方法:

利用遗传系统创造了一个缺乏mDA域的ACIII突变.
在整个细胞和隔离膜中评估了电子转移活性.
从大肠杆菌中异质地表达和净化mDA和ActE,用于氧化还原潜力分析.

主要成果:

缺乏mDA的ACIII突变体没有向cytochrome aa3氧化酶表现出电子转移活性.
mdA被确定为ActA五甲基核和细胞染色体aa3氧化酶之间的唯一电子载体.
确定了mdA和ActE中的heme的氧还原中点潜力,提供了对heme链排列的洞察力.

结论:

移动细胞染色体c域 (mdA) 对于从ACIII向细胞染色体a3氧化酶的复合体间电子转移是不可或缺的.
这项研究提供了ActA/ActE组件中血红素还原电位的第一个特征,澄清了电子转移路径.

关键词:

替代性复合体III 替代性复合体III 细胞染色体细胞染色体电子传输链是一种电子传输链.这种细菌是Flavobacterium johnsoniae.血红细胞的氧化还原潜力

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