Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We isolated a globomycin-resistant, temperature-sensitive mutant of Escherichia coli K-12 strain AB1157. The mutation mapped in dnaE, the structural gene for the alpha-subunit of DNA polymerase III. The in vivo processing of lipid-modified prolipoprotein was more resistant to globomycin in the mutant strain 307 than in its parent. The prolipoprotein signal peptidase activity was also increased twofold in the mutant, and there was a threefold increase in the activity of isoleucyl-tRNA synthetase. The results suggest that a mutation in dnaE may affect the expression of the ileS-lsp operon in E. coli. In addition, strain 307 showed a reduced level of streptomycin resistance compared with its parental strain AB1157 (rpsL31). Strain 307 was killed by streptomycin at a concentration of 200 micrograms/ml, which did not affect the rate of bulk protein synthesis in this mutant. A second mutation which was involved in the reduced streptomycin resistance in strain 307 was identified and found to be closely linked to or within the rpsD (ramA, ribosomal ambiguity) gene. Both dnaE and rpsD were required for the reduced streptomycin resistance in strain 307.
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PMID:Isolation and characterization of a new globomycin-resistant dnaE mutant of Escherichia coli. 311 19

Sequence organization and origin of HSV-1 strain Angelotti (ANG) class II defective DNA (HSV-1 ANG dDNA1) were examined in detail by establishing physical maps and by molecular cloning. dDNA1 consists of concatemers of tandem repeat units in which sequences from the UL region spanning map coordinates 0.37 to 0.415 of standard HSV ANG DNA are covalently linked to TRS/IRS sequences. The size of the repeat unit was determined to be about 8.9 kilobase pairs (kb), comprising sequences of 7.3 kb from UL and 1.6 kb from TRS/IRS regions. UL sequences were delineated by restriction enzyme sites KpnI N-P and EcoRI F-M, and were colinear with the corresponding sequences of the standard (wild-type) virus genome. Expression of dDNA1 was studied in African green monkey kidney cells and in Xenopus laevis oocytes. A major polypeptide of approx. mol. wt. 135 000 (135K) was overproduced, suggesting that this protein was encoded by dDNA1. By several parameters, e.g. size, immune cross-reactivity, and affinity for native and denatured DNA, the 135K polypeptide was identified as the major HSV DNA-binding protein. It was further shown that the repeat unit contains part of the DNA polymerase gene as demonstrated by its ability to rescue some mutations in this gene.
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PMID:Herpes simplex virus defective genomes: structure of HSV-1 ANG defective DNA of class II and encoded polypeptides. 631 66