precorrin-6B + NADP(+) <=> precorrin-6A + NADPH + 2 H(+)
precorrin-6b + nadp(+) <=> precorrin-6a + nadph + 2 h(+)
precorrin-6B + NADP(+) <=> precorrin-6A + NADPH + 2 H(+)
precorrin-6b + nadp(+) <=> precorrin-6a + nadph + 2 h(+)