Download MendeleyCrystal structures of Val58Ile tryptophan repressor in a domain-swapped array in the presence and absence of L-tryptophan.
Sprenger, J., Lawson, C.L., von Wachenfeldt, C., Lo Leggio, L., Carey, J.(2021) Acta Crystallogr F Struct Biol Commun 77: 215-225
- PubMed: 34196612
- DOI: https://doi.org/10.1107/S2053230X21006142
- Primary Citation of Related Structures:
6ST6, 6ST7, 7OS9 - PubMed Abstract:
The crystal structures of domain-swapped tryptophan repressor (TrpR) variant Val58Ile before and after soaking with the physiological ligand L-tryptophan (L-Trp) indicate that L-Trp occupies the same location in the domain-swapped form as in native dimeric TrpR and makes equivalent residue contacts. This result is unexpected because the ligand binding-site residues arise from three separate polypeptide chains in the domain-swapped form. This work represents the first published structure of a domain-swapped form of TrpR with L-Trp bound. The presented structures also show that the protein amino-terminus, whether or not it bears a disordered extension of about 20 residues, is accessible in the large solvent channels of the domain-swapped crystal form, as in the structures reported previously in this form for TrpR without N-terminal extensions. These findings inspire the exploration of L-Trp analogs and N-terminal modifications as labels to orient guest proteins that cannot otherwise be crystallized in the solvent channels of crystalline domain-swapped TrpR hosts for potential diffraction analysis.
Organizational Affiliation:
Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark.
