Location of Anabaena sp. strain L-31 kdp genes in p4AD3K and p2AD28K. The kdpB, kdpG, kdpC, and kdpD ORFs are shown by thick arrows. The p4AD3K insert contains the 3′ end of Anabaena kdpB, complete kdpG, kdpC, and 840 bp of the Anabaena kdpD gene. The p2AD28K insert shows a 974-bp overlap with the p4AD3K insert and contains the entire kdpD gene. Restriction sites: H, HindIII; C, ClaI; and E, EcoRV.