Chain A ( L590 P591 L592 P593 K594 S595 G596 L597 L598 L599 K600 S601 Q602 E603 L604 L605 T606 K607 L722 C723 E725 E726 M727 Q728 L729 L730 Q731 V732 Q733 S734 I737 L741 M846 F849 E850 M852 V853 V854 K855 V856 )