Rhodobacter changlensis sp. nov., a psychrotolerant, phototrophic alphaproteobacterium from the Himalayas of India.
(41/78)
A Gram-negative, non-motile, oval to rod-shaped, psychrotolerant, phototrophic, purple non-sulfur bacterium (designated strain JA139T) was isolated from a snow sample from Changla Pass in the Indian Himalayas. Strain JA139T had vesicular-type intracytoplasmic membrane structures and contained bacteriochlorophyll a and most probably spheroidene-like carotenoids. Biotin, niacin and thiamine were required for growth of strain JA139T. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that the strain clustered with species of the genus Rhodobacter but was distinctly separate from all recognized members of the family Rhodobacteraceae. Based on the genotypic and phenotypic differences observed between strain JA139T and recognized Rhodobacter species, strain JA139T is considered to represent a novel species of the genus, for which the name Rhodobacter changlensis sp. nov. is proposed. The type strain is JA139T (=DSM 18774T=CCUG 53722T=JCM 14338T). (+info)
Crystal structure of a protein, structurally related to glycosyltransferases, encoded in the Rhodobacter blasticus atp operon.
(42/78)
The F1-ATP synthase atp operon in the proteobacterium Rhodobacter blasticus contains six open reading frames, encoding six hypothetical proteins. Five of these subunits, in the stoichiometry (alphabeta)3gamma delta epsilon make up the catalytic F1-ATP synthase complex similarly in bacteria, chloroplasts and mitochondria. The sixth gene of the R. blasticus atp operon, urf6, shows very little sequence homology to any protein of known structure or function. The gene has previously been cloned, the product (called majastridin) has been heterologously expressed in Escherichia coli, and purified to high homogeneity [M. Brosche, I. Kalbina, M. Arnfelt, G. Benito, B.G. Karlsson, A. Strid, Occurrence, overexpression and partial purification of the protein (majastridin) corresponding to the URF6 gene of the Rhodobacter blasticus atp operon, Eur. J. Biochem. 255 (1998) 87-92]. We have solved the X-ray crystal structure and refined a model of majastridin to atomic resolution. Here we present the crystal structures of apo-majastridin and the complex of majastridin with Mn2+ and UDP and show that it has extensive structural similarity to glycosyltransferases (EC 2.4). This is the first structure determined from a new group of distantly related bacterial proteins of at least six members. They share the identical amino acids that bind Mn2+ and a triplet of amino acids in the putative sugar-binding site. (+info)
Structure, function and interactions of the PufX protein.
(43/78)