6ST7

Crystal Structure of Domain Swapped Trp Repressor V58I Variant with bound L-trp

Summary for 6ST7

• Entry DOI: 10.2210/pdb6st7/pdb
• Related: 1JHG 1MI7
• Descriptor: Trp operon repressor, TRYPTOPHAN, ISOPROPYL ALCOHOL, ... (4 entities in total)
• Functional Keywords: hostal, l-trp binding, domain swapping, dna binding protein
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 1
• Total formula weight: 12471.30

Authors

Sprenger, J.,Lawson, C.L.,Carey, J.,Drouard, F.,von Wachenfeldt, C.,Schulz, A.,Linse, S.,Lo Leggio, L. (deposition date: 2019-09-10, release date: 2020-09-30, Last modification date: 2024-01-24)

Primary citation

Sprenger, J.,Lawson, C.L.,von Wachenfeldt, C.,Lo Leggio, L.,Carey, J.
Crystal structures of Val58Ile tryptophan repressor in a domain-swapped array in the presence and absence of L-tryptophan.
Acta Crystallogr.,Sect.F, 77:215-225, 2021

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.

PubMed: 34196612
DOI: 10.1107/S2053230X21006142

Experimental method

X-RAY DIFFRACTION (2.45 Å)