Sequence alignment of RNA polymerase (RNAP) from T7, phiKMV, phi80-18, GAP227, phiAS7, and Ahp1 by ClustalW.

<p>Lines superposed over the alignment show the major features obtained experimentally for T7 RNAP. Black shadowed residues indicate functionally important residues in T7 RNAP. Boldface residues are highly conserved amino acids within known RNAP. Symbols: “*”, identical residues in all sequences, “:”, highly conserved residues, “.”, weakly conserved residues.