GENES FOR 2 SUBUNITS OF ACETYL-COENZYME A CARBOXYLASE OF ANABAENA SP STRAIN PCC 7120 - BIOTIN CARBOXYLASE AND BIOTIN CARBOXYL CARRIER PROTEIN

Genes for two subunits of acetyl-coenzyme A carboxylase, biotin carbox ylase and biotin carboxyl carrier protein, have been cloned from Anaba ena sp. strain PCC 7120. The two proteins are 181 and 447 amino acids long and show 40 and 57% identity to the corresponding Escherichia col i proteins, respectively. The sequence of the biotinylation site in An abaena sp. strain PCC 7120 is MetLysLeu, not the MetLysMet found in ot her sequences of biotin-dependent carboxylases. The amino acid sequenc e of biotin carboxylase is also very similar (32 to 47% identity) to t he sequence of the biotin carboxylase domain of other biotin-dependent carboxylases. Genes for these two subunits of acetyl-coenzyme A carbo xylase are not linked in Anabaena sp. strain PCC 7120, contrary to the situation in E. coli, in which they are in one operon.