x x x x x x
x x x x
x x x
x x x x
C C C C
x \ / x x \ / x
x Zn x x Zn x
C / \ C H / \ C
x x x x
x x x x x x x x x x x x x
'C': conserved cysteine involved zinc binding
'H': conserved histidine involved in zinc binding
'Zn': zinc atom