Chains and heterogens:
PDB Chain Sequences:
>1mrsA (A:) mliaiegvdgagkrtlveklsgafraagrsvatlafprygqsvaadiaaealhgehgdla ssvyamatlfaldragavhtiqglcrgydvvildryvasnaaysaarlhenaagkaaawv qriefarlglpkpdwqvllavsaelagersrgraqrdpgrardnyerdaelqqrtgavya elaaqgwggrwlvvgadvdpgrlaatla