The gene for 2-phosphoglycolate phosphatase (gph) in Escherichia coli is located in the same operon as dam and at least five other diverse genes

Downstream of the dam gene in the Escherichia coli genome the following thr ee genes are located: first rpe, then a gene encoding a 27 kDa protein and finally trpS. Here we present evidence that the 27 kDa protein has 2-phosph oglycolate phosphatase activity, and we name the gene gph. Phosphoglycolate phosphatase is needed in autotrophic organisms performing the Calvin-Benso n-Bassham (CBB) reductive pentose-phosphate cycle. E. coli is not capable o f autotrophic growth and probably utilizes Gph activity for other function( s) than in the CBB cycle. We found no physiological effect of deleting gph and its function in E. coli remains unclear. The use of fusion plasmids, wh ere lacZ was inserted into gph and trpS, and deletion derivatives of these fusion plasmids, showed that rpe, gph and trpS are all members of the dam-c ontaining operon. A novel promoter was identified in the distal part of the dam gene. The operon, which contains aroK, aroB, urf74.3, dam, rpe, gph, a nd trpS, can be termed a superoperon, since it consists of (at least) seven apparently unrelated genes which are under complex regulatory control. (C) 1999 Elsevier Science B.V. All rights reserved.