Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.9.3.1 (
cytochrome oxidase
)
8,822
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In yeast (
Saccharomyces cerevisiae
) and human (
Homo sapiens
) mitochondria, Oxidase assembly protein1 (Oxa1) is the general insertase for protein insertion from the matrix side into the inner membrane while Cytochrome
c
oxidase assembly protein18 (Cox18/Oxa2) is specifically involved in the topogenesis of the
complex IV
subunit, Cox2. Arabidopsis (
Arabidopsis thaliana
) mitochondria contain four OXA homologs: OXA1a, OXA1b, OXA2a, and OXA2b. OXA2a and OXA2b are unique members of the Oxa1 superfamily, in that they possess a tetratricopeptide repeat (TPR) domain at their C termini. Here, we determined the role of OXA2a by studying viable mutant plants generated by partial complementation of homozygous lethal
OXA2a
transfer-DNA insertional mutants using the developmentally regulated
ABSCISIC ACID INSENSITIVE3
(
ABI3
) promoter. The
ABI3p:OXA2a
plants displayed growth retardation due to a reduction in the steady-state abundances of both
c
-type cytochromes, cytochrome
c
1
and cytochrome
c
The observed reduction in the steady-state abundance of complex III could be attributed to cytochrome
c
1
being one of its subunits. Expression of a soluble heme lyase from an organism with cytochrome
c
maturation system III could functionally complement the lack of OXA2a. This implies that OXA2a is required for the system I cytochrome
c
maturation of Arabidopsis. Due to the interaction of OXA2a with Cytochrome
c
maturation protein CcmF C-terminal-like protein (CCMF
C
) in a yeast split-ubiquitin based interaction assay, we propose that OXA2a aids in the membrane insertion of CCMF
C
, which is presumed to form the heme lyase component of the cytochrome
c
maturation pathway. In contrast with the crucial role played by the TPR domain of OXA2b, the TPR domain of OXA2a is not essential for its functionality.
...
PMID:The OXA2a Insertase of Arabidopsis Is Required for Cytochrome
c
Maturation. 3275 71
