Chains and heterogens:
PDB Chain Sequences:
>2ctvA (A:) adtivaveldtypntdigdpsyphigidiksvrskktakwnmqngkvgtahiiynsvdkr lsavvsypnadsatvsydvdldnvlpewvrvglsastglyketntilswsftsklksnst hetnalhfmfnqfskdqkdlilqgdattgtdgnleltrvssngspqgssvgralfyapvh iwessavvasfeatftflikspdshpadgiaffisnidssipsgstgrllglfpdan