Chains and heterogens:
PDB Chain Sequences:
>1kugA (A:) qrfpqryielaivvdhgmytkyssnfkkirkrvhqmvsninemcrplniaitlalldvws ekdfitvqadapttaglfgdwrervllkkknhdhaqlltdtnfarntigwayvgrmcdek ysvavvkdhsskvfmvavtmthelghnlgmehddkdkckcttcimsavisdkqsklfsdc skdyyqtfltndnpqcilnap