Chains and heterogens:
PDB Chain Sequences:
>1sfiA (A:) ivggytcgantvpyqvslnsgyhfcggslinsqwvvsaahcyksgiqvrlgedninvveg neqfisasksivhpsynsntlnndimliklksaaslnsrvasislptscasagtqclisg wgntkssgtsypdvlkclkapilsdsscksaypgqitsnmfcagyleggkdscqgdsggp vvcsgklqgivswgsgcaqknkpgvytkvcnyvswikqtiasn