Chains and heterogens:
PDB Chain Sequences:
>1b2lA (A:) mdltnknvifvaalggigldtsrelvkrnlknfvildrvenptalaelkainpkvnitfh tydvtvpvaeskkllkkifdqlktvdilingagilddhqiertiainftglvntttaild fwdkrkggpggiianicsvtgfnaihqvpvysaskaavvsftnslaklapitgvtaysin pgitrtplvhtfnswldveprvaelllshptqtseqcgqnfvkaieankngaiwkldlgt leaiewtkhwdshi