3.4.21.92 A153C the structure of a crosslinked Escherichia coli ClpP are determined in which the two heptameric rings of ClpP are held together by disulfide bonds. While all Escherichia coli ClpP structures solved to date are in the extended state, the crosslinked ClpP structure is found to be in the compact state. Under reducing condition Km (N-succinyl-Leu-Tyr-7-amido-4-methylcoumarin) is similar to wild-type but kcat is 32fold lower. Under non-reducing conditions mutant is inactive and does not bind its cognate chaperone 718406 3.4.21.92 A153P crystallization data, disruption of handle region resulting in an altered ring-ring dimerization interface 669324 3.4.21.92 Delta1-10 deletion of the N-terminal 10, 14, or 17 residues of mature ClpP allows these mutants to degrade alpha-casein, a natively unfolded protein 717989 3.4.21.92 DELTA1-14 deletion of the N-terminal 10, 14, or 17 residues of mature ClpP allows these mutants to degrade alpha-casein, a natively unfolded protein 717989 3.4.21.92 DELTA1-17 deletion of the N-terminal 10, 14, or 17 residues of mature ClpP allows these mutants to degrade alpha-casein, a natively unfolded protein 717989 3.4.21.92 E135A mutant shows no activity 717089 3.4.21.92 E135R mutant shows no activity 717089 3.4.21.92 E8A/R12A/E14A/R15A residues 8-15 form the channel loop of the pore: when charged residues in the channel (amino acids 8-15) are changed with alanine this mutant cleaves the decapeptide at a rate 8fold faster than observed with wild-type ClpP but cleaves the dipeptide at a comparable rate. Mutant shows a substantial GFP-ssrA degradation similar to wild-type 717989 3.4.21.92 E8G/Q9G/T10G/S11G/R12G/G13G/E14G/R15G residues 8-15 form the channel loop of the pore: when replaced with eight glycines this mutant cleaves the decapeptide at a rate 8fold faster than observed with wild-type ClpP but cleaves the dipeptide at a comparable rate. Mutant shows a much slower degradation of GFP-ssrA 717989 3.4.21.92 E8G/R12G/E14G/R15G residues 8-15 form the channel loop of the pore: when charged residues in the channel (amino acids 8-15) are changed with glycine this mutant cleaves the decapeptide at a rate 8fold faster than observed with wild-type ClpP but cleaves the dipeptide at a comparable rate. Mutant shows a much slower degradation of GFP-ssrA 717989