Molecular analysis of an outer membrane protein, MopB, of Methylococcus capsulatus (Bath) and structural comparisons with proteins of the OmpA family.

Autor: Fjellbirkeland, Anne, Bemanian, Vahid, McDonald, Ian R., Murrell, J. Colin, Jensen, Harald B.
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Zdroj: Archives of Microbiology; Jun2000, Vol. 173 Issue 5/6, p346-351, 6p
Abstrakt: The gene encoding a major outer membrane protein (MopB) of the methanotroph Methylococcus capsulatus (Bath) was cloned and sequenced. The cloned DNA contained an open reading frame of 1044 bp coding for a 348-amino-acid polypeptide with a 21-amino-acid leader peptide. Comparative sequence analysis of the predicted amino acid sequence revealed that the C-terminal part of MopB possessed sequences that are conserved in the OmpA family of proteins. The N-terminal half of the protein had no significant sequence similarity to other proteins in the databases, but the predicted secondary structure showed stretches of amphipathic β-strands typical of transmembrane segments of outer membrane proteins. A region with four cysteines similar to the cysteine-encompassing region of the OprF of Pseudomonas aeruginosa was found toward the C-terminal part of MopB. Results from whole-cell labeling with the fluorescent thiol-reacting reagent 5-iodoacetamidofluorescein indicated a surface-exposed location for these cysteines. A probe consisting of the 3′-end of the mopB gene hybridized to the type I methanotroph Methylomonas methanica S1 in Southern blots containing DNA from nine methanotrophic strains representing six different genera. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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