Chains and heterogens:
PDB Chain Sequences:
>1cr4A (A:) mrerirehlsseesvgllfsgctgindktlgarggevimvtsgsgmgkstfvrqqalqwg tamgkkvglamleesveetaedliglhnrvrlrqsdslkreiiengkfdqwfdelfgndt fhlydsfaeaetdrllaklaymrsglgcdviildhisivvsasgesderkmidnlmtklk gfakstgvvlvvichlknpdkgkaheegrpvsitdlrgsgalrqlsdtiialernqqgdm pnlvlvrilkcrftgdtgiagymeynketgwlepssy
>1cr4A (A:) mrerirehlsseesvgllfsgctgindktlgarggevimvtsgsgmgkstfvrqqalqwg tamgkkvglamleesveetaedliglhnrvrlrqsdslkreiiengkfdqwfdelfgndt fhlydsfaeaetdrllaklaymrsglgcdviildhisirkmidnlmtklkgfakstgvvl vvichlkdlrggalrqlsdtiialernqlvlvrilkcrftgdtgiagymeynketgwlep ssy