Intermolecular cleavage by UmuD-like mutagenesis proteins

• DOI: 10.1073/pnas.95.4.1478
• Publication Date: 2002-07-26T14:42:40Z
• Authors: John P. McDonald; Ekaterina G. Frank; Arthur S. Levine; Roger Woodgate
• Keywords: Repressor lexA; Cleavage (geology); SOS response

The activity of a number proteins is regulated by self-processing reactions. Elegant examples are the cleavage prokaryotic LexA and lambdaCI transcriptional repressors UmuD-like mutagenesis proteins. Various studies support hypothesis that reactions predominantly intramolecular in nature. recently described crystal structure Escherichia coli UmuD' protein (the posttranslational product UmuD protein) suggests, however, region corresponding to site at least 50 A away from catalytic active site. We considered possibility, therefore, might undergo that, contrast lambdaCI, occurs via an intermolecular rather than reaction. To test this hypothesis, we introduced into E. compatible plasmids with mutations either or three Cleavage these only presence both plasmids, indicating reaction indeed Furthermore, completely dependent upon multifunctional RecA leads restoration cellular nonmutable strains. Intermolecular biotinylated mutant was also observed vitro wild-type protein, addition intact normal (UmuD') can act as classical enzyme.