MBA1 encodes a mitochondrial membrane‐associated protein required for biogenesis of the respiratory chain

[摘要]

The yeast MBA1 gene (ulti-copy ypass of FG3) is one of three genes whose overexpression suppresses afg3-null and rcal-null mutations. Bypass of AFG3 and RCA1, whose products are essential for assembly of mitochondrial inner membrane enzyme complexes, suggests a related role for MBA1. The predicted translation product is a 30 kDa hydrophilic protein with a putative mitochondrial targeting sequence and no homology to any sequence in protein or EST databases. Gene disruption leads to a partial respiratory growth defect, which is more pronounced at temperatures above 30°C. Concomitantly, amounts of cytochromes b and aa3 are reduced. A C-terminal c-myc-tagged MBA1 gene product is functional and is found associated with the mitochondrial inner membrane, from which it can be extracted by carbonate, but not by high salt. These observations give further support to a role of MBA1 in assembly of the respiratory chain.

[学科分类] 生物化学/生物物理

[关键词] Respiratory chain;Assembly;Cytochrome;AFG3;RCA1;Saccharomyces cerevisiae