The spectral properties of cytochrome c oxidase have been the subject of a number of studies (1-14). Although these studies have not, in themselves, convinced all investigators that more than one hemoprotein was involved, they have confirmed the original observations which formed the basis for distinguishing the cytochromes a and u3. These observations by Keilin and Hartree (1) indicated that t...

The analysis of steps of genetic transcription and translation specifying certain of the chloroplast components of the unicellular green alga, Chlamydomonas reinhardi, has been the subject of several publications from this laboratory (1, 4, 7-10, 13, 16, 17). The cytochromes are of particular interest in this regard, for the chloroplasts of C. reinhardi contain at least three -cytochrome 553, c...

The metal-reducing bacterium Shewanella putrefaciens MR-1 is known to localize a majority of its membrane-bound cytochromes to its outer membrane when grown under anaerobic conditions. In this study, pyridine hemochrome spectra confirmed that these outer membrane cytochromes are c-type, and electrophoretic data demonstrated the presence of four distinct outer membrane cytochromes, with apparent...

Very few studies have been conducted on alkaline adaptation of Gram-negative alkaliphiles. The reversed difference of H(+) concentration across the membrane will make energy production considerably difficult for Gram-negative as well as Gram-positive bacteria. Cells of the alkaliphilic Gram-negative bacterium Pseudomonas alcaliphila AL15-21(T) grown at pH 10 under low-aeration intensity have a ...

Cytochromes c are metalloproteins that function in electron transfer reactions and contain a heme moiety covalently attached via thioether linkages between the co-factor and a CXXCH motif in the protein. Covalent attachment of the heme group occurs on the positive side of all energy-transducing membranes (bacterial periplasm, mitochondrial intermembrane space and thylakoid lumen) and requires m...

1. The ole-3 mutant of Saccharomyces cerevisiae has an early lesion in the pathway of porphyrin biosynthesis. 2. This results in the loss of all haem-containing enzymes, including the mitochondrial cytochromes, and prevents the synthesis of components whose formation requires haem-containing enzymes, including unsaturated fatty acids, ergosterol and methionine. 3. The pleiotropic effects of the...

Kusaka, Takashi (National Institute for Leprosy Research, Tokyo, Japan), Ryo Sato, and Ko Shoji. Comparison of cytochromes in mycobacteria grown in vitro and in vivo. J. Bacteriol. 87:1383-1388. 1964.-Spectrophotometric investigations were made on cell suspensions or particulate fractions of four species of mycobacteria which had been cultivated in vitro. The results obtained indicated the pres...

A plasma membrane iron reductase, required for cellular iron acquisition by Saccharomyces cerevisiae, and the human phagocytic NADPH oxidase, implicated in cellular defense, contain low potential plasma membrane b cytochromes that share elements of structure and function. Four critical histidine residues in the FRE1 protein of the iron reductase were identified by site-directed mutagenesis. Ind...