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Identification of the activating region of catabolite gene activator protein (CAP): isolation and characterization of mutants of CAP specifically defective in transcription activation.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1993 Jul 01; Vol. 90 (13), pp. 6081-5. - Publication Year :
- 1993
-
Abstract
- We have isolated 21 mutants of catabolite gene activator protein (CAP) defective in transcription activation at the lac promoter but not defective in DNA binding. The amino acid substitutions in the mutants map to a single region of CAP: amino acids 156-162. As assessed in vitro, the substituted CAP variants are nearly completely unable to activate transcription at the lac promoter but bind to DNA with the same affinity and bend DNA to the same extent as wild-type CAP. Our results establish that amino acids 156-162 are critical for transcription activation at the lac promoter but not for DNA binding and DNA bending. In the structure of CAP, amino acids 156-162 are part of a surface loop. We propose that this surface loop makes a direct protein-protein contact with RNA polymerase at the lac promoter.
- Subjects :
- Base Sequence
Cyclic AMP Receptor Protein chemistry
Cyclic AMP Receptor Protein genetics
DNA chemistry
DNA metabolism
DNA-Directed RNA Polymerases metabolism
Lac Operon
Models, Molecular
Molecular Sequence Data
Mutation
Nucleic Acid Conformation
Promoter Regions, Genetic
Structure-Activity Relationship
Cyclic AMP Receptor Protein physiology
Peptide Fragments physiology
Transcriptional Activation
Subjects
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 90
- Issue :
- 13
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 8392187
- Full Text :
- https://doi.org/10.1073/pnas.90.13.6081