Cytochrome c oxidase contains an extra charged amino acid cluster in a new type of respiratory chain in the amino-acid-producing Gram-positive bacterium Corynebacterium glutamicum The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this paper are AB052748 and AB052749.

Abstract

The membranes fromTo characterize complex IV, cytochrome c oxidase and its structural genes were isolated. The oxidase is of the cytochrome aa 3 type, but mass spectrometry indicated that the haem is haem As, which contains a geranylgeranyl sidechain instead of a farnesyl group. The enzyme is a SoxM-type haem-copper oxidase composed of three subunits. Edman degradation and mass spectrometry suggested that the N-terminal signal sequence of subunit II is cleaved and that the new N-terminal cysteine residue is diacylglycerated, while neither subunit I nor subunit III is significantly modified. The genes for subunits II (ctaC) and III (ctaE) are located upstream of the qcrCAB operon, while that for subunit I (ctaD) is located separately. The oxidase showed low enzyme activity with extrinsic substrates such as cytochromes c from horse heart or yeast, and has the Cu A -binding motif in its subunit II. A prominent structural feature is the insertion of an extra charged amino acid cluster between the β2 and β4 strands in the substrate-binding domain of subunit II. The β2-β4 loop of this oxidase is about 30 residues longer than that of major cytochrome c oxidases from mitochondria and proteobacteria, and is rich in both acidic and basic residues. These findings suggest that the extra charged cluster may play a role in the interaction of the oxidase with the cytochrome c subunit of the new type of bc complex.

Evidence for a cytochrome bcc–aa 3 interaction in the respiratory chain of Mycobacterium smegmatis

“…The work presented here provides the biochemical evidence for this proposal. The gene sequence of cytochrome c 1 of the M. smegmatis bc 1 complex indicates the presence of a second cytochrome c, as previously seen for C. glutamicum and Rhodococcus rhodochrous (Niebisch & Bott, 2001;Sakamoto et al, 2001;Sone et al, 2003). Analysis of the complete M. tuberculosis genome and the partial genome of M. smegmatis indicates the absence of any independent membrane-bound or soluble cytochromes c in these species, as in other acid-fast bacteria (Niebisch & Bott, 2001;Sakamoto et al, 2001;Sone et al, 2003).…”

“…The hypothesis was put forth that these enlarged domains mediate an interaction between the bcc complex and the terminal oxidase that precludes the necessity for an independent cytochrome c. This has been verified in C. glutamicum by activity assays and the co-isolation of the bcc complex and an aa 3 -type cytochrome oxidase complex (Niebisch & Bott, 2003). As shown by Sakamoto et al (2001), the genes for the bc 1 complex and the haem-Cu oxidase of mycobacteria are very similar to those of corynebacteria, suggesting a similar scenario.…”

“…The acid-fast bacteria, including Mycobacterium spp., have structural similarities to both Gram-positive and Gramnegative bacteria. The genomes of the Corynebacterium, Mycobacterium and Rhodococcus species examined encode neither soluble cytochrome c nor an independent membranebound cytochrome c (Niebisch & Bott, 2001;Sakamoto et al, 2001;Sone et al, 2003). Analysis of the Corynebacterium glutamicum genes encoding its bc 1 complex and its haem-Cutype oxidase revealed two modified components .…”

Electron Transfer Ability from NADH to Menaquinone and from NADPH to Oxygen of Type II NADH Dehydrogenase ofCorynebacterium glutamicum

“…19) The Gram-positive coryne-form bacterium Corynebacterium glutamicum is an amino acid producing strain used industrially for the production of L-lysine and Lglutamate. The respiratory chain of this bacterium consists of several different primary dehydrogenases, 20,21) such as NADH dehydrogenase, succinate dehydrogenase, L-lactate dehydrogenase, and malate: quinone oxidoreductase, and at least three terminal oxidases, CN-sensitive cytochrome aa 3 , 22,23) CN-resistant bypass oxidase, 20) and cytochrome bd. 24) The NADH y To whom correspondence should be addressed.…”

Function of the Cytochrome bc 1 - aa 3 Branch of the Respiratory Network in Mycobacteria and Network Adaptation Occurring in Response to Its Disruption

“…In contrast, little is currently known about the CcOterminating branch in mycobacteria. Genome comparisons suggest that its structure resembles those of other nocardio-form actinomycetes, such as Corynebacterium glutamicum (7,18,19,29,35) and Rhodococcus rhodochrous (36), which are distinguished by the fact that the cytochrome c 1 (QcrC) in these organisms is a distinct, diheme c-type cytochrome (18,35).…”