Abstract
1. (1) The hisS gene of Salmonella typhimurium is the structural gene for histidyl-tRNA synthetase. Mutants in the hisS gene have an altered histidyl-tRNA synthetase and constitute one of the four classes of histidine regulatory mutants. 2. (2) Mutant hisS1520 has a synthetase with a 50-fold decreased affinity for histidine. This mutant has a markedly decreased growth rate on minimal medium and is de-repressed for the biosynthetic enzymes of the histidine operon. Both of these properties appear to reflect the decreased amount of charged histidine-specific tRNA due to the mutant synthetase. The amount of histidyl-tRNA can be increased in this mutant by swelling its internal pool of histidine, and this swelling results in restoration of the normal growth rate and repression of the operon. These results support the idea that histidyl-tRNA is more directly connected with the repression of the histidine operon than histidine itself. 3. (3) Levels of the histidyl-tRNA synthetase are unaffected by de-repression of the histidine operon.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 325-334 |
| Number of pages | 10 |
| Journal | Journal of Molecular Biology |
| Volume | 22 |
| Issue number | 2 |
| State | Published - Dec 28 1966 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Virology
Cite this
Histidine regulatory mutants in Salmonella typhimurium. II. Histidine regulatory mutants having altered histidyl-tRNA synthetase. / Roth, John R.; Ames, Bruce N.
In: Journal of Molecular Biology, Vol. 22, No. 2, 28.12.1966, p. 325-334.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Histidine regulatory mutants in Salmonella typhimurium. II. Histidine regulatory mutants having altered histidyl-tRNA synthetase
AU - Roth, John R.
AU - Ames, Bruce N.
PY - 1966/12/28
Y1 - 1966/12/28
N2 - 1. (1) The hisS gene of Salmonella typhimurium is the structural gene for histidyl-tRNA synthetase. Mutants in the hisS gene have an altered histidyl-tRNA synthetase and constitute one of the four classes of histidine regulatory mutants. 2. (2) Mutant hisS1520 has a synthetase with a 50-fold decreased affinity for histidine. This mutant has a markedly decreased growth rate on minimal medium and is de-repressed for the biosynthetic enzymes of the histidine operon. Both of these properties appear to reflect the decreased amount of charged histidine-specific tRNA due to the mutant synthetase. The amount of histidyl-tRNA can be increased in this mutant by swelling its internal pool of histidine, and this swelling results in restoration of the normal growth rate and repression of the operon. These results support the idea that histidyl-tRNA is more directly connected with the repression of the histidine operon than histidine itself. 3. (3) Levels of the histidyl-tRNA synthetase are unaffected by de-repression of the histidine operon.
AB - 1. (1) The hisS gene of Salmonella typhimurium is the structural gene for histidyl-tRNA synthetase. Mutants in the hisS gene have an altered histidyl-tRNA synthetase and constitute one of the four classes of histidine regulatory mutants. 2. (2) Mutant hisS1520 has a synthetase with a 50-fold decreased affinity for histidine. This mutant has a markedly decreased growth rate on minimal medium and is de-repressed for the biosynthetic enzymes of the histidine operon. Both of these properties appear to reflect the decreased amount of charged histidine-specific tRNA due to the mutant synthetase. The amount of histidyl-tRNA can be increased in this mutant by swelling its internal pool of histidine, and this swelling results in restoration of the normal growth rate and repression of the operon. These results support the idea that histidyl-tRNA is more directly connected with the repression of the histidine operon than histidine itself. 3. (3) Levels of the histidyl-tRNA synthetase are unaffected by de-repression of the histidine operon.
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M3 - Article
C2 - 5339688
AN - SCOPUS:0014030851
VL - 22
SP - 325
EP - 334
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 2
ER -