FIG. 5.

(A) Amino acid sequence comparisons of NblB with two hypothetical proteins of Synechocystis sp. strain PCC 6803 (sll1663 and slr1687) (33), CpcE from S. elongatus (Se CpcE) (accession no. p50037), CpcE from Pseudanabaena (Pa CpcE) (20), CpcE from Synechocystis sp. strain 6803 (Sy CpcE) (slr1878) (33), and two hypothetical proteins from the methanobacteria (Mth 1 and Mth 2) (48). Amino acids identical between the NblB sequence and 30% or more of the other sequences presented are in a black background, while conserved amino acids are in a gray background. (B) Homology among the E-Z motif and the three repeat units, designated boxes 1, 2, and 3, of NblB. Identical residues are in a black background, while conserved residues are in a gray background. The position of the first amino acid of each repeat sequence is indicated. Alignments were performed with the Genetics Computer Group (Madison, Wis.) sequence analysis package.