Chains and heterogens:
PDB Chain Sequences:
>1b90A (A:) avngkgmnpdykaylmaplkkipevtnwetfendlrwakqngfyaitvdfwwgdmekngd qqfdfsyaqrfaqsvknagmkmipiisthqcggnvgddcnvpipswvwnqksddslyfks etgtvnketlnplasdvirkeygelytafaaamkpykdviakiylsggpagelrypsytt sdgtgypsrgkfqaytefakskfrlwvlnkygslnevnkawgtkliselailppsdgeqf lmngylsmygkdylewyqgilenhtkligelahnafdttfqvpigakiagvhwqynnpti phgaekpagyndyshlldafksakldvtftclemtdkgsypeysmpktlvqniatlanek givlngenalsigneeeykrvaemafnynfagftllryqdvmynnslmgkfkdllgvtpv mqtivvknvpttigdtvyitgnraelgswdtkqypiqlyydshsndwrgnvvlpaernie fkafikskdgtvkswqtiqqswnpvplkttshtssw