Degradation of missense mutant beta-galactosidase proteins in Escherichia coli K-12.

Ten out of 43 missense mutations in the lacZ gene of Escherchia coli gave rise to polypeptide chains that were degraded in vivo. While many of the mutants appeared to be fully or partially CRM-, there appeared to be no obvious correlation between degradation, map position, altered subunit association and the half-life of the mutant proteins.