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Your search keyword '"Cricco JA"' showing total 2 results
Start Over Author "Cricco JA" Topic alkyl and aryl transferases
2 results on '"Cricco JA"'

1. The Trypanosoma cruzi proteins TcCox10 and TcCox15 catalyze the formation of heme A in the yeast Saccharomyces cerevisiae.

Author

Buchensky C, Almirón P, Mantilla BS, Silber AM, and Cricco JA

Subjects
Alkyl and Aryl Transferases chemistry, Alkyl and Aryl Transferases genetics, Amino Acid Sequence, Animals, Base Sequence, Cloning, Molecular, Cytochrome b Group chemistry, Cytochrome b Group genetics, Heme biosynthesis, Heme genetics, Mitochondria metabolism, Mitochondrial Membranes metabolism, Polymerase Chain Reaction, Protozoan Proteins chemistry, Protozoan Proteins genetics, RNA, Messenger analysis, RNA, Messenger genetics, Saccharomyces cerevisiae metabolism, Trypanosoma cruzi genetics, Trypanosoma cruzi growth & development, Trypanosoma cruzi metabolism, Alkyl and Aryl Transferases metabolism, Cytochrome b Group metabolism, Heme analogs & derivatives, Protozoan Proteins metabolism, Saccharomyces cerevisiae genetics, Trypanosoma cruzi enzymology
Abstract

Trypanosoma cruzi, the etiologic agent for Chagas’ disease, has requirements for several cofactors, one of which is heme. Because this organism is unable to synthesize heme, which serves as a prosthetic group for several heme proteins (including the respiratory chain complexes), it therefore must be acquired from the environment. Considering this deficiency, it is an open question as to how heme A, the essential cofactor for eukaryotic CcO enzymes, is acquired by this parasite. In the present work, we provide evidence for the presence and functionality of genes coding for heme O and heme A synthases, which catalyze the synthesis of heme O and its conversion into heme A, respectively. The functions of these T. cruzi proteins were evaluated using yeast complementation assays, and the mRNA levels of their respective genes were analyzed at the different T. cruzi life stages. It was observed that the amount of mRNA coding for these proteins changes during the parasite life cycle, suggesting that this variation could reflect different respiratory requirements in the different parasite life stages., (© 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

Published
2010
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2. Heme O synthase and heme A synthase from Bacillus subtilis and Rhodobacter sphaeroides interact in Escherichia coli.

Author

Brown BM, Wang Z, Brown KR, Cricco JA, and Hegg EL

Subjects
Alkyl and Aryl Transferases isolation & purification, Bacterial Proteins genetics, Bacterial Proteins isolation & purification, Cloning, Molecular, Cytochrome b Group genetics, Cytochrome b Group isolation & purification, Cytochrome b Group metabolism, Electron Transport Complex IV metabolism, Ferrochelatase genetics, Ferrochelatase isolation & purification, Heme metabolism, Membrane Proteins genetics, Membrane Proteins isolation & purification, Membrane Proteins metabolism, Molecular Sequence Data, Open Reading Frames, Protein Prenylation, Rhodobacter sphaeroides genetics, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism, Alkyl and Aryl Transferases metabolism, Bacillus subtilis enzymology, Bacterial Proteins metabolism, Escherichia coli enzymology, Ferrochelatase metabolism, Heme analogs & derivatives, Rhodobacter sphaeroides enzymology
Abstract

Cytochrome c oxidase requires multiple heme and copper cofactors to catalyze the reduction of molecular oxygen to water. Although significant progress has been made in understanding the transport and incorporation of the copper ions, considerably less is known about the trafficking and insertion of the heme cofactors. Heme O synthase (HOS) and heme A synthase (HAS) from Rhodobacter sphaeroides (Cox10 and Cox15, respectively) and Bacillus subtilis (CtaB and CtaA, respectively) have been cloned and expressed in Escherichia coli. Our results demonstrate that HOS copurifies with HAS and that HAS copurifies with HOS, indicating that HOS and HAS interact and may form a physiologically relevant complex in vivo. Consistent with this hypothesis, the presence of HAS alters the total level of farnesylated hemes, providing further evidence that HOS and HAS interact. Our current working model is that HOS and HAS form a complex and that heme O is transferred directly from HOS to HAS. Because of the strong sequence similarity and evolutionary relationship between R. sphaeroides and mitochondria, our data suggest that this complex may form in eukaryotes as well.

Published
2004
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