The complete amino acid sequence of rubredoxin from the green phototrophic bacterium Chlorobium thiosulphatophilum strain PM

Abstract

A complete amino acid sequence for the rubredoxin from the photosynthetic bacterium Chlorobium thiosulphatophilum is proposed. The sequence, a single polypeptide chain of 53 amino acids, was deduced from the sequences of peptides obtained by chymotryptic, tryptic, thermolytic or mild acid digestion.The rubredoxin shows a high degree of sequence homology with rubredoxins from non-photosynthetic bacteria, and the evolutionary implications of this are considered. [6]. Clostridium thermoaceticum has been shown (uniquely) to contain two distinct rubredoxins [7]. The molecular masses of all these proteins are about 6 kDa and the redox potentials about -50 mV at pH 7.0. Amino acid sequences have been reported for the rubredoxins from P . aerogenes [8], D . gigas [9], M . elsdenii [lo], D . vulgaris [ l l ] and C . pasteurianum [12].All these rubredoxins contain a single iron atom, but no inorganic sulphur. X-ray structure analysis showed that the iron atom is tetrahedrally chelated to the sulphur atoms of the four cysteine residues in the amino acid chain [13 -171.Only two rubredoxins have been isolated from obligate aerobes; Pseudomonas oleovorans [18] and Acinetobacter calcoaceticus [19]. The Ps. oleovorans rubredoxin is unusual in that it is about twice the size of the C. pasteurianum rubredoxin; sequence data suggest that this was caused by an ancestral gene duplication [20]. The Ps. oZeovorans rubredoxin has been shown to function as an electron carrier in an enzyme system that hydroxylates alkanes and fatty acids [18,21]. The alkane-oxidizing system of Ac. calcoaceticus may function in a similar manner [22]. In contrast the functional role of rubredoxin in anaerobic bacteria is largely unknown, although there is some evidence to suggest that it is the preferred electron donor for carbon monoxide dehydrogenase in Cl. thermoaceticum [23, 241. Rubredoxin has not been detected in the purple sulphur or non-sulphur photosynthetic bacteria, but appears to be generally present in green sulphur bacteria isolated rubredoxin from the green sulphur bacterium Chlorobium thiosulphatophilum, the complete amino acid sequence of which is reported in the present paper.

Rubredoxin from the Green Sulfur Bacterium Chlorobium tepidum Functions as an Electron Acceptor for Pyruvate Ferredoxin Oxidoreductase

“…1C), with a native molecular weight of 250,000 Ϯ 10,000, as determined by gel filtration. The N-terminal amino acid sequence of the C. tepidum Rd was determined to be MQKWVCVPCGY-DPAD-, which indicated high similarity with other previously isolated Rds of anaerobic bacteria (30,31,43,44). The midpoint reduction potential value of C. tepidum Rd, Ϫ87 mV (Fig.…”

“…In the presence of 0.1 M NaCl, the molecular weight increased to 13,000 Ϯ 1,000, indicating that the protein exists as a monomer at high ionic strength. The amino acid composition of C. tepidum Rd also yielded an approximate molecular weight of 6,500 (data not shown), which is typical of other Rds (30,31,(43)(44)(45). Electrophoresis of the purified Rd gave rise to a single protein band (Fig.…”

Identification and characterization of a eukaryotically encoded rubredoxin in a cryptomonad alga1

“…ClustalW alignment [37] of rd proteins from G. theta (this work, CAB40406), Arabidopsis ([22], AAD25628), Synechocystis sp. strain PCC6803 ([7], BAA17090), Anabaena variabilis (unpublished, CAB45645), Azotobacter chroococcum ([38], P48343), Alcaligenes eutrophus ([39], P31912), Chlorobium limicola ([40], P09947), Butyribacterium methylotrophicum ([41], P14071), C. pasteurianum ([42], P00268), D. vulgaris ([43], P00269), Methylobacterium thermoautotrophicum ([44], AAB84661) and P. furiosus ([45], P24297) using the ‘blosum62’ weight matrix, a gap opening penalty of 20 and a gap extension penalty of 0.1. Conserved amino acids in all sequences are shaded black, conserved amino acids in at least 50% of the compared sequences are shaded gray.…”

X‐ray crystal structures of the oxidized and reduced forms of the rubredoxin from the marine hyperthermophilic archaebacterium pyrococcus furiosus

“…RdDv, Desulfovibrio vulgaris (Bruschi, 1976b); RdCp, Clostridium pasteurianum (Watenpaugh et al, 1973;Yasunobo & Tanaka, 1983); RdDd, Desulfovibrio desulfuricans( Horme1 et al, 1986); Cpf, CIostridiumperf~ingens (Seki et al, 1989); Cts, Clostridium thermosaccharolyticum (Meyer et al, 1990); Cbt, Chlorobium thiosulfatophilum (Woolley et al, 1987); DvM, D. vulgaris strain Miyazaki (Shimizu et al, 1989); DvH, D. vulgaris strain Hildenborough (Bruschi, 1976b;Voordouw, 1988); Me, Megasphaera elsdenii (Bachmeyer et al, 1968b); Pa, Peptococcus aerogenes (Bachmeyer et al, 1968a); Bm, Butyribacterium methylotrophicum (Saeki et al, 1989). …”