Table 2.

Distances (Å) from M_A to Selected Residues in Azoarcus (Azo1 and Azo2, PDB Accession Numbers 1U6B and 1ZZN, Respectively) and Twort (Two, PBD Accession Number 1Y0Q) Crystal Structures

residue (Tetrahymena numbering)a	corresponding residue (Azo)	distance in Azo1	distance in Azo2	corresponding residue (Two)	distance in Two
C208SP	C88	2.3	2.2	U84	3.8
C208RP	C88	4.4	3.9	U84	4.8
A304SP	G170	2.5	2.1	A185	2.9
A304RP	G170	4.4	4.2	A185	5.2
A306SP	A172	2.1	2.2	A187	2.8
A306RP	A172	2.8	3.8	A187	3.3
U307SP	U173	4.4	4.4	U188	2.8
U307RP	U173	6.9	6.8	U188	4.9

^aResidues in bold represent putative M_A ligands.