Bacterium strain and plasmid

PROBLEM TO BE SOLVED: To obtain a new strain whose chromosome has one or more mutations influencing on a system formed with cya gene and a DNA sequence controlling the expression of the cya gene and which is useful for producing medicines containing proteins as active ingredients. SOLUTION: This new strain is an Escherichia coil deposited as an accession number I-525 to C.N.C.M and has a chromosome having one or more mutations giving influences to a system formed with cya gene and a DNA sequence for controlling the expression of the cya gene. The new strain can be applied to many technical fields, and is especially useful for producing medicines containing proteins as active ingredients. The strain is obtained by introducing a plasmid into an Escherichia coil to transform the Escherichia coil. The plasmid is prepared by ligating a DNA section originated from plasmid pBR 322 to a DNA section coding the precursor of a natural human growth hormone(hGH) and a DNA section containing a promoter, an operator, etc. COPYRIGHT: (C)1997,JPO