Disease relevance of COX11

• Two of these mutations are likely to occlude a surface pocket behind the copper-binding domain in Cox11p, based on analogy with the Sinorhizobium meliloti Cox11 solution structure, thereby suggesting that this pocket is crucial for Cox11p function [1].

High impact information on COX11

• The COX11 protein is tightly associated with the mitochondrial membrane but is not a component of purified cytochrome oxidase [2].
• The antibody recognizes a 28 kd protein in yeast mitochondria, consistent with the size of the protein predicted from the sequence of COX11 [2].
• Cytochrome oxidase assembly in yeast requires the product of COX11, a homolog of the P. denitrificans protein encoded by ORF3 [2].
• In the present study we demonstrate the existence in yeast of a second nuclear gene, COX11, whose encoded protein is homologous to another open reading frame (ORF3) present in the same operon of P. denitrificans [2].
• In this and in other respects cox11 and cox10 mutants have very similar phenotypes [2].

Biological context of COX11

• Allelism of PSO7/COX11 was verified by non-complementation of 4NQO-sensitivity in diploids homo- and hetero-allelic for the pso7-1 and cox11::TRP1 mutant alleles [3].
• The oxidase that assembled in the absence of Cox11p lacked Cu(B) at the active site and contained greatly reduced amounts of metal at the magnesium/manganese-binding site between subunits I and II [4].
• Of the nine PSO genes of yeast seven apparently encode proteins involved in the repair of DNA lesions generated by photoinduced psoralens and by other mutagens, while two, PSO6 and PSO7, are responsible for structural elements of the membrane and for a functional respiratory chain, respectively [5].
• The yeast gene PSO7 was cloned from a genomic library by complementation of the pso7-1 mutant's sensitivity phenotype to 4-nitroquinoline-1-oxide (4NQO) [3].
• Recent progress in elucidating the molecular structure of the PSSO genes PSO2 to PSO7 is presented [6].

Anatomical context of COX11

• Evidence for the association of yeast mitochondrial ribosomes with Cox11p, a protein required for the Cu(B) site formation of cytochrome c oxidase [7].

Associations of COX11 with chemical compounds

• This evidence suggests that the COX11 protein may be another heme A biosynthetic enzyme involved in forming the formyl group at position 8 of the porphyrin ring [8].
• Cox17 is a 69-residue cysteine-rich, copper-binding protein that has been implicated in the delivery of copper to the Cu(A) and Cu(B) centers of cytochrome c oxidase via the copper-binding proteins Sco1 and Cox11, respectively [9].
• A novel mutant isolate of Saccharomyces cerevisiae, sensitive to photoactivated mono- and bi-functional psoralens, to UV at 254 nm (UVC), and to nitrosoguanidine, was found to complement the photoactivated psoralen-sensitivity phenotype conferred by the pso1- pso7 mutations and was therefore named pso8-1 [10].

Physical interactions of COX11

• The copper domain of Cox11 may be an important docking motif for Cox1 or a Cox1-associated protein [11].

Other interactions of COX11

• On the functions of the yeast COX10 and COX11 gene products [8].
• A number of conserved, positively charged residues may interact with complementary surfaces on Sco1 and Cox11, facilitating docking and copper transfer [9].
• Fusion of the N terminus of Cox11 to the matrix ribosomal protein Rsm22 results in a functional protein capable of suppressing the respiratory defect of both Deltacox11 cells and Deltarsm22 cells [11].
• We propose a model in which the Cu(B) site is co-translationally formed by a transient interaction between Cox11p and the nascent Cox1p in the intermembrane space [7].

Analytical, diagnostic and therapeutic context of COX11

• Sequence analysis revealed that PSO7 is allelic to the 1.1-kb ORF of the yeast gene COX11 which is located on chromosome XVI and encodes a protein of 28-kDa localized in the inner mitochondrial membrane [3].

References