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Bacillus subtilis membrane-bound holo-cytochrome c-550 was found to be expressed from the structural gene cloned on a plasmid vector in aerobically grown Escherichia coli and exhibited normal biochemical properties. This occurs despite the lack of endogenous eytochrome c and suggests that eytochrome c-heme lyase activity is also present in aerobic E. coli. The membrane topology of B. subtilis eyto
Little is known about c-type cytochromosomes 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
Cytochrome 5558 in the cytoplasmic membrane ofBacilius subtiiis constitutes the anchor and electronacceptor to the flavoprotein (Fp) and iron-sulphurprotein (Ip) in succinate:quinone oxidoreductase, andseemingly contains two haem groups. EPR and MCDspectroscopic data indicate bis-imidazole ligation ofthe haem. Apo-cytochrome was found in the mem-brane fraction of haem-deficient B. subtilis, sugges
A 3.8-kilobase DNA fragment from Bacillus subtilis containing the hemA gene has been cloned and sequenced. Four open reading frames were identified. The first is hemA, encoding a protein of 50.8 kilodaltons. The primary defect of a B. subtilis 5-aminolevulinic acid-requiring mutant was identified as a cysteine-to-tyrosine substitution in the HemA protein. The predicted amino acid sequence of the B
The aecA and aecB loci map at 250 and 290 degrees, respectively, on the Bacillus subtilis chromosomal genetic map. The aecB locus has been proposed as the structural gene for aspartokinase II. From DNA sequence analyses and comparisons to the sequence of the aspartokinase II gene, it can be concluded that the structural gene for aspartokinase II is located close to sdh at 250 degrees and cannot be
The 2-oxoglutarate dehydrogenase complex consists of three different subenzymes, the E1o (2-oxoglutarate dehydrogenase) component, the E2o (dihydrolipoyl transsuccinylase) component, and the E3 (dihydrolipoamide dehydrogenase) component. In Bacillus subtilis, the E1o and E2o subenzymes are encoded by odhA and odhB, respectively. A plasmid with a 6.8-kilobase-pair DNA fragment containing odhA and o
Mammalian and Escherichia coli succinate dehydrogenase (SDH) and E. coli fumarate reductase apparentlycontain an essential cysteine residue at the active site, as shown by substrate-protectable inactivation withthiol-specific reagents. Bacillus subtilis SDH was found to be resistant to this type of reagent and containsan alanine residue at the amino acid position equivalent to the only invariant c
6-Hydroxy-d-nicotine oxidase (6-HDNO) of Arthrobacter oxydans, an enzyme inducible by dl-nicotine, contains FAD covalently bound via an 8α-N(3)His linkage. Expression of the gene encoding 6-HDNO and flavinylation of the protein were studied in Bacillus subtilis. In this heterologous system the following findings were made. 1. An enzymically active covalently flavinylated 6-HDNO of normal size can
The membranebound tricarboxylic acid cycle enzyme succinate dehydrogenase (SDH) is associated with a b-type cytochrome in many organisms. 1,2 The cytochrome b is often found in stoichiometric amounts in isolated succinate-ubiquinone oxidoreductase (complex II) from bovine heart,3Neurospora crassa,4Ascaris suum5 and plant6 mitochondria as well as in SDH complexes isolated from both Gram-negative an
Membrane-bound succinate oxidoreductases are flavoenzymes containing one each of a 2Fe, a 3Fe and a 4Fe iron-sulfur center. Amino acid sequence homologies indicate that all three centers are located in the Ip (B) subunit. From polypeptide and gene analysis of Bacillus subtillis succinate dehydrogenase-defective mutants combined with earlier EPR spectroscopic data, we show that four conserved cyste
The 2-oxoglutarate dehydrogenase multienzyme complex is composed of three different subenzymes: 2-oxoglutarate dehydrogenase (E1o), dihydrolipoamide transsuccinylase (E2o), and dihydrolipoamide dehydrogenase (E3). Bacillus subtilis E1o and E2o are encoded by the citK and citM genes, respectively. A 3.4-kb BamHI DNA fragment containing citK and citM markers was isolated from a library of B. subtili
Bacillus subtilis succinate dehydrogenase is bound to the cytoplasmic membrane by cytochrome b-558, a 23-kDa transmembrane protein which also functions as electron acceptor to the dehydrogenase. The structural gene for the apocytochrome, sdhC, has previously been cloned and sequenced. In this work the structure and translation of cytochrome b-558 was studied in different sdhC mutants. Mutant cytoc
The DNA sequence of the Bacillus subtilis sdh operon coding for the two succinate dehydrogenase subunits and cytochrome b-558 (the membrane anchor protein) has recently been established. We have now determined the extent of N-terminal processing of each polypeptide by radiosequence analysis. At the same time, direct evidence for the correctness of the predicted reading frames has been obtained. Th
Plasmid pKIM2 carries the Bacillus subtilis sdh operon and adjacent regions of the bacterial chromosome. The plasmid replicates in Escherichia coli but not in B. subtilis. Different portions of the sdh operon were removed from pKIM2 and replaced by a cat gene derived from pC194. A series of plasmids carrying sdh deletions was thus derived. Plasmid DNA was linearized at restriction sites within the
The nucleotide sequence of a 2.7-kilobase segment of DNA containing the sdhA and sdhB genes encoding the flavoprotein (Fp, sdhA) and iron-sulfur protein (Ip, sdhB) subunits of the succinate dehydrogenase of Bacillus subtilis was determined. This sequence extends the previously reported sequence encoding the cytochrome b558 subunit (sdhC) and completes the sequence of the sdh operon, sdhCAB. The pr
AbstractThe 2-oxoglutarate dehydrogenase complex of the tricarboxylic acid cycle (TCA) consists of multiple copies of 3 different subenzymes; E1, E2 and E3. The E3 subenzyme is also a component of the pyruvate dehydrogenase complex. Bacillus subtilis 2-oxoglutarate dehydrogenase mutants were studied. The mutants defective in E1, E2 and E3 subenzyme activity, respectively, could be separated into 3
This chapter discusses the molecular properties, genetics, and biosynthesis of Bacillus subtilis succinate dehydrogenase complex. The citric acid cycle enzyme succinate dehydrogenase (SDH) is a membrane-bound iron-sulfur flavoprotein. Mitochondrial and bacterial SDH and membrane-bound fumarate reductase in anaerobic and facultative bacteria are similar in composition. SDH and also fumarate reducta
