Genetic engineering of phytochrome biosynthesis in bacteria.
Authors Gambetta G A; Lagarias J C;
JournalProc Natl Acad Sci U S A
PubMed ID11553807
The bilin prosthetic groups of the phytochrome photoreceptors and the light-harvesting phycobiliprotein antennae arise from the oxygen-dependent ring opening of heme. Two ferredoxin-dependent enzymes contribute to this conversion: a heme oxygenase and a bilin reductase with discrete double-bond specificity. Using a dual plasmid system, one expressing a truncated cyanobacterial apophytochrome ... More
Cysteinyl-tRNA synthetase is not essential for viability of the archaeon Methanococcus maripaludis.
Authors Stathopoulos C; Kim W; Li T; Anderson I; Deutsch B; Palioura S; Whitman W; Söll D;
JournalProc Natl Acad Sci U S A
PubMed ID11717392
The methanogenic archaea Methanocaldococcus jannaschii and Methanothermobacter thermautotrophicus contain a dual-specificity prolyl-tRNA synthetase (ProCysRS) that accurately forms both prolyl-tRNA (Pro-tRNA) and cysteinyl-tRNA (Cys-tRNA) suitable for in vivo translation. This intriguing enzyme may even perform its dual role in organisms that possess a canonical single-specificity cysteinyl-tRNA synthetase (CysRS), raising the question ... More
Allurin, a 21-kDa sperm chemoattractant from Xenopus egg jelly, is related to mammalian sperm-binding proteins.
Authors Olson J H; Xiang X; Ziegert T; Kittelson A; Rawls A; Bieber A L; Chandler D E;
JournalProc Natl Acad Sci U S A
PubMed ID11562501
Previously, we demonstrated that a protein from Xenopus egg jelly exhibits sperm chemoattractant activity when assayed by either video microscopy or by sperm passage across a porous filter. Here we describe the isolation and purification of allurin, the protein responsible for this activity. Freshly oviposited jellied eggs were soaked in ... More
Functional cloning, heterologous expression, and purification of two different N-deoxyribosyltransferases from Lactobacillus helveticus.
Authors Kaminski Pierre Alexandre;
JournalJ Biol Chem
PubMed ID11836245
Lactobacillus helveticus contains two types of N-deoxyribosyltransferases: DRTase I catalyzes the transfer of 2'-deoxyribose between purine bases exclusively whereas DRTase II is able to transfer the 2'-deoxyribose between two pyrimidine or between pyrimidine and purine bases. An Escherichia coli strain, auxotrophic for guanine and unable to use deoxyguanosine as source ... More