Isolation of the temperature-sensitive @entity526 mutant 72c has been described previously. The mutant allele was named fusB and causes a pleiotropic phenotype, the most striking features of which, besides temperature sensitivity, are the inability to grow on synthetic medium and supersensitivity to @entity206 , an antibiotic that inhibits the C1 metabolism. This work shows that the fusB mutation is a frameshift mutation in the nadD gene that encodes @entity65674 adenylyltransferase. The frameshift leads to a change of the last 10 @entity1522 and an addition of 17 @entity1522 . This lesion, renamed nadD72, leads to very little @entity2125 + and @entity1110 synthesis at the permissive temperature and essentially no synthesis at the non-permissive temperature. As a comparison, a new mutation in the nadD gene, with an @entity535 change in the @entity855 -binding site, has been isolated. Its @entity2125 + synthesis is decreased at 30 degrees C but the level is still sufficient to support normal growth. At 42 degrees C, @entity2125 + synthesis is reduced further, which leads to temperature sensitivity on minimal medium. This mutation was designated nadD74. Thus, a small decrease in @entity2125 + levels affects ability to grow on minimal medium at 42 degrees C, while a large decrease leads to a more pleiotropic phenotype.

fusB is an allele of nadD, encoding @entity65674 adenylyltransferase in XXXX .

@entity2125 :: ('MESH:D009243', 'Chemical') :: ['NAD'] @entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity65674 :: ('MESH:C002953', 'Chemical') :: ['nicotinate mononucleotide'] @entity526 :: ('562', 'Species') :: ['Escherichia coli'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity1110 :: ('MESH:D009249', 'Chemical') :: ['NADPH'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['ATP'] @entity206 :: ('MESH:D014295', 'Chemical') :: ['trimethoprim']
@entity526 :: (562,Species) :: ['Escherichia coli']
