Chains and heterogens:
PDB Chain Sequences:
>1tnk_ (-) ivggytcgantvpyqvslnsgyhfcggslinsqwvvsaahcyksgiqvrlgedninvveg neqfisasksivhpsynsntlnndimliklksaaslnsrvasislptscasagtqclisg wgntkssgtsypdvlkclkapilsdsscksaypgqitsnmfcagyleggkdscqgdsggp vvcsgklqgivswgsgcaqknkpgvytkvcnyvswikqtiasn