TABLE 1.

Amino acid changes introduced into domain VI

Alteration	Rationalea
K1651A	Invariant catalytic residue of motif X; essential in RrmJ
G1674A	Critical residue of the signature GxGxG SAM-binding motif
D1762A	Invariant catalytic residue of motif IV
K1795A	Invariant catalytic residue of motif VI; essential in Rrm J
E1833A	Invariant catalytic residue of motif VIII; minor role in Rrm J
E1833Q	Maintain size

^aMotifs X, IV, VI, and VIII are highlighted in Fig. 1A and correspond to the SAM-dependent MTase superfamily (53).