Coq7p relevant residues for protein activity and stability.
Coenzyme Q (Q) is an isoprenylated benzoquinone electron carrier required for electronic transport in the mitochondrial respiratory chain, shuttling electrons from complexes I and II to complex III. Q synthesis requires proteins termed Coq (Coq1-Coq11). Coq7p is part of the multimeric complex involved in Q synthesis catalyzing the hydroxylation of demethoxy-Q6 (DMQ6), the last monooxygenase step in Q synthesis with a catalytic center containing a carboxylate-bridged di-iron at the active site of the enzyme. Here we indicate a group of Coq7p residues that modulate protein activity: D53, R57, V111 and S114. R57, V111 and S114 are very conserved residues; V111 and S114 are present in separated communities of amino acid correlation analysis. The coq7 double mutant V111G/S114A and S114E show respiratory deficiency at non permissive temperature, DMQ6 accumulation and lower content of Q6. Therefore we conclude that phosphomimetic S114E inhibit Coq7p activity, and propose that S114 phosphorylation is required to move a non-structured loop of 25 amino acids between helix 2 and 3, and that affects the di-iron coordination in Coq7p catalytic center.
Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil; COBIO, Universidade Tecnológica Federal do Paraná - UTFPR, Dois Vizinhos, Paraná, Brazil.
Cleverson
C
Busso
Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, Brazil.
José Ribamar
JR
Ferreira-Júnior
Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
Janaina A
JA
Paulela
Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Lucas
L
Bleicher
Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, Brazil.
Marilene
M
Demasi
Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil. Electronic address: mariohb@usp.br.
Mario H
MH
Barros
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D055162:Biocatalysis; D017124:Conserved Sequence; D004795:Enzyme Stability; D006358:Hot Temperature / Q000009:adverse effects; D006900:Hydroxylation; D051336:Mitochondrial Membranes / Q000201:enzymology* / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D019159:Nonheme Iron Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010802:Phylogeny; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014451:Ubiquinone / Q000096:biosynthesis*
C097734:CAT5 protein, S cerevisiae; D019159:Nonheme Iron Proteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C032165:ubiquinone 6; D014451:Ubiquinone
Coenzyme Q; Coq7p; Phosphorylation