Chains and heterogens:
PDB Chain Sequences:
>3r99A (A:) tplvhvasvekgrsyedfqkvynaialklreddeydnyigygpvlvrlawhtsgtwdkhd ntggsyggtyrfkkefndpsnaglqngfkflepihkefpwissgdlfslggvtavqemqg pkipwrcgrvdtpedttpdngrlpdadkdadyvrtffqrlnmndrevvalmgahalgkth lknsgyegpwgaannvftnefylnllnedwklekndanneqwdsksgymmlptdysliqd pkylsivkeyandqdkffkdfskafekllengitfpkdapspfifktleeqgl