Chains and heterogens:
PDB Chain Sequences:
>1cu4H (H:) kvklqqsgaelvrsgasvklsctasgfnikdyyiqwvkqrpeqglewigwidpengnsey aprfqgkatmtadtlsntaylqlssltsedtavyycnadlhdywgqgttltvssakttap svyplapvcgdttgssvtlgclvkgyfpepvtltwnsgslssgvhtfpavlqsdlytlss svtvtsstwpsqsitcnvahpasstkvdkkieprvts
>1cu4H (H:) klqqsgaelvrsgasvklsctasgfnikdyyiqwvkqrpeqglewigwidpengnseyap rfqgkatmtadtlsntaylqlssltsedtavyycnadlhdywgqgttltvssakttapsv yplapvcgdttgssvtlgclvkgyfpepvtltwnsgslssgvhtfpavlqsdlytlsssv tvtsstwpsqsitcnvahpasstkvdkkieprvts
>1cu4L (L:) dvvmtqtplslsvtigqpasisckssqslldsdgktyliwvfqrpgqspkrliflvskrd sgvpdrftgsgsgtdftlkisrveaedvgvyycwqgthfphtvgggtkleiaradaaptv sifppsseqltsggasvvcflnnfypkdinvkwkidgserqngvlnswtdqdskdstysm sstltltkdeyerhnsytceathktstspivksfnrnec