A systematic review was conducted to examine the associations in Pneumocystis jirovecii pneumonia (PCP) patients between dihydropteroate synthase (DHPS) mutations and sulfa or sulfone (sulfa) prophylaxis and between DHPS mutations and sulfa treatment outcome. Selection criteria included study populations composed entirely of PCP patients and mutation or treatment outcome results for all patient...

The FAD1 gene of Saccharomyces cerevisiae has been selected from a genomic library on the basis of its ability to partially correct the respiratory defect of pet mutants previously assigned to complementation group G178. Mutants in this group display a reduced level of flavin adenine dinucleotide (FAD) and an increased level of flavin mononucleotide (FMN) in mitochondria. The restoration of res...

Adomet synthetase (EC 2.5.1.6) catalyzes the formation of Adomet, which serves as a methyl group donor in highly specific transmethylation reactions involving a11 kinds of acceptor molecules such as proteins, nucleic acids, phenylpropanoid derivatives, polysaccharides, cyclic fatty acids, etc. Adomet also plays a role in amino acid biosynthesis and polyamine biosynthesis. In plants, Adomet has ...

We have purified the product of the NAM2 gene, the mitochondrial leucyl-tRNA synthetase, from yeast mitochondria. The purified protein cross-reacts with antibodies raised against the product of a LacZ/NAM2 gene fusion and antibodies raised against the purified Escherichia coli leucyl-tRNA synthetase. The mass as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis is about 10...

Glutamine synthetase could be repressed several hundredfold rather than 6- to 10-fold as previously reported. Ammonia was not the primary repression signal for glutamine synthetase. Repression appeared to be mediated by a high level of glutamine and probably by a high ratio of glutamine to alpha-ketoglutarate. Mutations in glnA (the structural gene for glutamine synthetase) were seen to fall in...

We have examined three mutants of Klebsiella aerogenes whose genetic lesions (glnB, glnD, and glnE) are in loci unlinked to the structural gene for glutamine sythetase (glnA) and in which the control of both the level and state of adenylylation of glutamine synthetase is altered. Each mutation alters a different component of the adenylylation system of glutamine synthetase [L-glutamate:ammonia ...

The structural gene for glutamine synthetase (glnA) in Bacillus subtilis ( glnAB ) cloned in the lambda vector phage Charon 4A was used to transduce a lysogenic glutamine auxotrophic Escherichia coli strain to prototrophy. The defective E. coli gene ( glnAE ) was still present in the transductant since it could be transduced. In addition, curing of the prototroph resulted in the restoration of ...

W e have isolated temperature resistant revertants from temperature sensitive E. coli strains containing either a thermolabile g lutaminyltRNA synthetase or leucyl-tRNA synthetase. Among the revertants which still contained the thermolabile leucyl-tRNA shynthetase w e found two classes of regulatory mutants (leuX and leuY) which have elevated levels of this enzyme. T h e leuX mutation specifies...

The DNA sequence of the Escherichia coli metK gene has been determined. Protein sequence data for purified S-adenosylmethionine synthetase have also been obtained and confirm that metK is the structural gene for S-adenosylmethionine synthetase in E. coli. The sequence of the amino-terminal 35 residues of purified S-adenosylmethionine synthetase localizes the beginning of the coding region of th...