Chains and heterogens:
PDB Chain Sequences:
>2d21A (A:) kieegklviwingdkgynglaevgkkfekdtgikvtvehpdkleekfpqvaatgdgpdii fwahdrfggyaqsgllaeitpdkafqdklypftwdavryngkliaypiavealsliynkd llpnppktweeipaldkelkakgksalmfnlqepyftwpliaadggyafkyengkydikd vgvdnagakagltflvdliknkhmnadtdysiaeaafnkgetamtingpwawsnidtskv nygvtvlptfkgqpskpfvgvlsaginaaspnkelakeflenylltdegleavnkdkplg avalksyeeelakdpriaatmenaqkgeimpnipqmsafwyavrtavinaasgrqtvdea lkdaqtritk