COXX_RHOSH Heme B farnesyltransferase ctaB Heme O synthase Converts heme B (protoheme IX) to heme O by substitution of the vinyl group on carbon 2 of heme B porphyrin ring with a hydroxyethyl farnesyl side group (By similarity). 284 Protoheme IX farnesyltransferase MSLVVFTALVGLLVAPVTVHPMIALTGILFIALGAGASGALNMWSHEDIDRVMKRTRNRPVPSGTVAPGEALGIGLALSGIAVVMLGLATNLFAAGLLAFTIFFYAVVYSMWLKRTTPQNIVIGGAAGAFPPMIGWAVATGGVSVESLFMFALIFMWTPPHFWSLALFMKSDYSDAGVPMLTVTHGRRVTRAHVLVYSLLLAPLAVAGAFTGTGGPLYLATALALNGWLLVGAVRTWRRDEAQAEADRYRVEKAFFRFSLYYLFLHFGAILAEAALKPYGLGGW