Document Detail

Bacillus subtilis 13-kilodalton cytochrome c-550 encoded by cccA consists of a membrane-anchor and a heme domain.
MedLine Citation:
PMID:  2166045     Owner:  NLM     Status:  MEDLINE    
Little is known about c-type cytochromes in Gram-positive bacteria in contrast to the wealth of information available on this type of cytochrome in Gram-negative bacteria and in eucaryotes. In the present work, the strictly aerobic bacterium Bacillus subtilis was analyzed for subcellular localization and number of different cytochromes c. In vivo labeling with radioactive 5-aminolevulinic acid, a precursor to heme, showed that the proteins containing covalently bound heme are predominantly found in the membrane fraction. One major membrane-bound cytochrome c of about 15 kDa and with an alpha-band absorption peak in the reduced state at 550 nm was analyzed in more detail. Cytochrome c-550 has the properties of an integral membrane protein. The physiological function of this relatively high redox potential cytochrome is not known. Its structural gene, cccA, was cloned, sequenced, and overexpressed in B. subtilis. The gene maps adjacent to rpoD (sigA) at 223 degrees on the chromosome. The amino acid sequence of cytochrome c-550 as deduced from the DNA sequence consists of 120 residues and contains one heme c binding site (Cys-Ile-Ala-Cys-His) located approximately in the middle of the polypeptide. From the hydropathy distribution and from comparisons to soluble c-type cytochromes of known three-dimensional structure, cytochrome c-550 seemingly consists of two domains; an N-terminal membrane-anchor domain and a C-terminal heme domain. A model for the topography of the cytochrome in the cytoplasmic membrane is suggested in which the N-terminal part spans the membrane in the form of a single segment in an alpha-helical conformation and the C-terminal heme domain is exposed on the extracytoplasmic side of the membrane. Deletion of cccA from the chromosome revealed another membrane-bound cytochrome with absorption maximum at 550 nm in the reduced state. Analysis of cccA deletion mutants demonstrated that the cytochrome c-550 encoded by cccA is not essential for growth of B. subtilis on rich or minimal media.
C von Wachenfeldt; L Hederstedt
Related Documents :
20632935 - Mechanism of steroidogenic electron transport: role of conserved glu429 in destabilizat...
16303765 - Protein kinase a-mediated phosphorylation modulates cytochrome c oxidase function and a...
6324795 - The mechanism of antibody inhibition of proton pumping by cytochrome oxidase vesicles.
10837475 - Characterization of ypmq, an accessory protein required for the expression of cytochrom...
9504975 - Molluscicidal and anti-ache activity of tertiary mixtures of pesticides
10049785 - Human phenylalanyl-trna synthetase: cloning, characterization of the deduced amino acid...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  265     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1990 Aug 
Date Detail:
Created Date:  1990-09-13     Completed Date:  1990-09-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  13939-48     Citation Subset:  IM    
Department of Microbiology, Univsrsity of Lund, Sweden.
Data Bank Information
Bank Name/Acc. No.:
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Sequence
Bacillus subtilis / genetics*,  metabolism
Base Sequence
Cell Membrane / metabolism
Chromatography, Ion Exchange
Chromosome Deletion
Chromosomes, Bacterial
Cloning, Molecular
Cytochrome c Group / genetics*,  isolation & purification,  metabolism
Electrophoresis, Polyacrylamide Gel
Escherichia coli / genetics
Genes, Bacterial*
Genetic Vectors
Heme / metabolism
Molecular Sequence Data
Molecular Weight
Protein Biosynthesis
Protein Conformation
Restriction Mapping
Sequence Homology, Nucleic Acid
Transcription, Genetic
Reg. No./Substance:
0/Cytochrome c Group; 14875-96-8/Heme; 9064-80-6/cytochrome C-550

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  A nuclear protein derived from brain cells stimulates transcription of the human neurotropic virus p...
Next Document:  Heterogeneity of cell surface endothelin receptors.