Penicillin-binding proteins ofRhodospirillum rubrum

Myers, Charles R.; Collins, Mary Lynne Perille

doi:10.1007/bf01573469

Cited by 9 publications

(6 citation statements)

References 41 publications

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“…7) confirmed a prominent separation of the various subcellular fractions. An absolute separation of these subcellular compartments has not been achieved in any bacterium, but these S. putrefaciens fractions are separated to an extent similar to that reported for other bacteria (15,16,19,33,34,44,45,52,53) and are comparable to the analogous fractions from previous experiments (35)(36)(37).…”

Section: Resultssupporting

confidence: 83%

Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1

1997

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The cymA gene, which encodes a tetraheme cytochrome c, was cloned from Shewanella putrefaciens MR-1. This gene complemented a mutant which had a TnphoA insertion in cymA and which was deficient in the respiratory reduction of iron(III), nitrate, fumarate, and manganese(IV). The 561-bp nucleotide sequence of cymA encodes a protein of 187 amino acids with a predicted molecular mass of 20.8 kDa. No N-terminal signal sequence was readily apparent; consistent with this, a cytochrome with a size of 21 kDa was detected in the wild type but was absent in the insertional mutant. The cymA gene is transcribed into an mRNA; the major transcript was approximately 790 bases, suggesting that it is not part of a multicistronic operon. This RNA transcript was not detected in the cymA mutant. The CymA protein was found in the cytoplasmic membrane and soluble fraction of MR-1, and it shares partial amino acid sequence homology with multiheme c-type cytochromes from other bacteria. These cytochromes are ostensibly involved in the transfer of electrons from the cytoplasmic membrane to acceptors in the periplasm. The localization of the fumarate and iron(III) reductases to the periplasm and outer membrane of MR-1, respectively, suggests the possibility of a similar electron transfer role for CymA.

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Section: Resultssupporting

confidence: 83%

Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1

1997

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“…To assess the relative degree of purification of the membrane fractions, the activities of three CM-specific enzymes (NADH oxidase, ATPase, and SDH) were determined in the CM, IM, and OM fractions of MR-1. Specific SDH activity was an average of 9-fold greater in the CM than in the OM; this distribution compares with a 7.7to 102-fold enrichment of SDH in the CM reported for various other gram-negative bacteria (11,16,17,39,49,50,54). Specific activities of NADH oxidase and ATPase were also markedly higher in the CM of MR-1 than in the OM; once again, the distributions resemble those of other organisms (47,50,56).…”

Section: Discussionsupporting

confidence: 64%

“…In addition to the CM and OM, a membrane band of intermediate density was also isolated; this intermediate band was a hybrid of CM and OM (see below) and will henceforth be referred to as IM. Such intermediate hybrid membrane fractions have been observed in other bacteria (5,27,38,39,50) and may represent adhesion sites between CM and OM termed Bayer's junctions (5,7,8,39).…”

Section: Characterization Of Membrane Fractions Prepared By Thementioning

confidence: 75%

“…In both aerobic and anaerobic cells, the specific activities of the enzymes NADH oxidase and ATPase, both of which are considered markers of the CM (47, 50, 56), were highest in the CM fractions ( Table 1). The specific activity of succinate dehydrogenase (SDH), another CM-specific enzyme (11,16,17,39,49,50,54), was an average of ninefold higher in the CM than in the OM (data not shown). The buoyant density and protein/phospholipid ratio were lowest in the CM and highest in the OM (Table 1); the observed values for both are in good agreement with those reported for other bacteria (15,27,47,49,50,54,56).…”

Section: Characterization Of Membrane Fractions Prepared By Thementioning

confidence: 99%

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Localization of cytochromes to the outer membrane of anaerobically grown Shewanella putrefaciens MR-1

1992

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In gram-negative bacteria, numerous cell functions, including respiration-linked electron transport, have been ascribed to the cytoplasmic membrane. Gram-negative bacteria which use solid substrates (e.g., oxidized manganese or iron) as terminal electron acceptors for anaerobic respiration are presented with a unique problem: they must somehow establish an electron transport link across the outer membrane between large particulate metal oxides and the electron transport chain in the cytoplasmic membrane. When the metal-reducing bacterium Shewanella putrefaciens MR-1 is grown under anaerobic conditions and membrane fractions are purified from cells lysed by an EDTA-lysozyme-polyoxyethylene cetyl ether (Brij 58) protocol, approximately 80% of its membrane-bound cytochromes are localized in its outer membrane. These outer membrane cytochromes could not be dislodged by treatment with chaotropic agents or by increased concentrations of the nonionic detergent Brij 58, suggesting that they are integral membrane proteins. Cytochrome distribution in cells lysed by a French press protocol confirm the localization of cytochromes to the outer membrane of anaerobically grown cells. This novel cytochrome distribution could play a key role in the anaerobic respiratory capabilities of this bacterium, especially in its ability to mediate manganese and iron reduction.

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“…Membranes from induced U7 contained little or no DVHEC and showed no peaks in the 800-to 900-nm range. The minor spectral peak at 410 nm, which was present principally in the soluble fractions of all strains (data not shown), corresponds to the Soret band of cytochromes (14,15,45).…”

Section: Construction Of Clonesmentioning

confidence: 99%

Construction, characterization, and complementation of Rhodospirillum rubrum puf region mutants

1991

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Rhodospirillum rubrum is a facultatively phototrophic bacterium that, under certain growth conditions, forms an intracytoplasmic chromatophore membrane (ICM) housing the photochemical apparatus. The puf operon of R. rubrum encodes protein subunits of the photochemical reaction center and the B880 lightharvesting antenna complex. Mutant strains of R. rubrum were constructed by interposon mutagenesis through which a kanamycin resistance gene cartridge was inserted into restriction sites and in place of restriction fragments of the pufregion. Southern blot analysis demonstrated that the defective copies ofpuf sequences had replaced their normal chromosomal counterparts through homologous recombination. The pheriotypes of the mutant strains were evaluated on the basis of puf gene expression, spectral analysis, pigment content of membranes, and electron-microscopic examination of thin sections of cells grown under semiaerobic and dark anaerobic conditions. Alterations of the puf region affect phototrophic competence and the formation of the ICM. The latter result implies an obligatory role for puf gene products in ICM formation in R. rubrum. One mutant with a deletion in puf structural genes was complemented in trans to the wild-type phenotype. Other mutants could be restored to the wild-type phenotype only by recombination.Rhodospirillum rubrum is a gram-negative, facultatively phototrophic, purple nonsulfur bacterium that grows chemoheterotrophically under aerobic conditions and phototrophically under reduced-oxygen conditions in the light. During the transition from aerobic to reduced-oxygen conditions, photopigments and associated proteins are synthesized and inserted into a differentiated intracytoplasmic chromatophore membrane (ICM). Previous studies have demonstrated that the photosynthetic ICM is physically continuous with (31) and formed by invagination of (16,17,27) the cytoplasmic membrane.Contained within the ICM of R. rubrum are two proteinpigment complexes, the P870 reaction center complex (RC) and the B880 light-harvesting I complex. The RC of R. rubrum consists of three polypeptide subunits, L, M, and H, which are present in a 1:1:1 ratio. Associated with these polypeptides are bacteriochlorophyll (BCHL), bacteriopheophytin, the carotenoid spirilloxanthin (CRT), iron, and ubiquinone (58, 59). R. rubrum has only one antenna complex, the B880 antenna complex, composed of ot and ,B polypeptides, BCHL, CRT, diphosphatidylethanolamine, and diphosphatidylglycerol (50).The genes encoding the B880 ot and polypeptides, and those encoding the reaction center L and M polypeptides, have been cloned and sequenced in Rhodobacter capsulatus (66, 67), Rhodobacter sphaeroides (35, 61, 62), R. rubrum (7, 10), and Rhodopseudomonas viridis (40, 60). These genes are closely linked in a single operon termed puf. The pufL and pufM genes of R. rubrum, Rhodopseudomonas viridis, Rhodobacter sphaeroides, and Rhodobacter capsulatus show a nucleotide sequence similarity ranging from 61 to 78% (7,10,35,60,66,67). R. rubrum puf seq...

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Penicillin-binding proteins ofRhodospirillum rubrum

Cited by 9 publications

References 41 publications

Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1

Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1

Localization of cytochromes to the outer membrane of anaerobically grown Shewanella putrefaciens MR-1

Construction, characterization, and complementation of Rhodospirillum rubrum puf region mutants

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