>4q50A (A:) observed residues (from ATOM records)
alsltadqmvsalldaeppilysmmglltnladrelvhminwakrvpgfvdltlhdqvhl
lecawleilmiglvwrsmehpkllfapnllldrnqgkgmveifdmllatssrfrmmnlqg
eefvclksiillnsgvysleekdhihrvldkitdtlihlmakagltlqqqhqrlaqllli
lshirhmsnkgmehlysvvplyglllemld