Patent ID: 9493558
Filing Date: 2016-11-15
CPC Classification: C07K,C12N,C12P,Y02P

Claim Text:
1. A recombinant gram-negative bacterial cell comprising a mutant spr gene encoding a mutant spr protein containing a mutation that is an amino acid substitution at one or more amino acids within the spr protein, wherein the cell comprises a non-recombinant wild-type chromosomal Tsp gene and expression of said mutant spr gene causes the cell to exhibit increased yield of a recombinant protein of interest or reduced lysis as compared to a wild-type bacterial cell containing a wild-type spr gene and expressing a protein of interest and, optionally, one or more of: a) a mutated DegP gene encoding a DegP protein having chaperone activity and reduced protease activity; b) a mutated ptr gene, wherein the mutated ptr gene encodes a Protease III protein having reduced protease activity or is a knockout mutated ptr gene; c) a mutated OmpT gene, wherein the mutated OmpT gene encodes an OmpT protein having reduced protease activity or is a knockout mutated OmpT gene; d) a recombinant polynucleotide encoding DsbC; and e) a polynucleotide encoding a protein of interest.