4Y6W: Crystal Structure Of Podosopora Anserina Putative Kinesin Light Chain Nearly Identical Tpr-like Repeats

Linear repeat proteins often have high structural similarity and low ( approximately 25%) pairwise sequence identities (PSI) among modules. We identified a unique P. anserina (Pa) sequence with tetratricopeptide repeat (TPR) homology, which contains longer (42 residue) repeats (42PRs) with an average PSI >91%. We determined the crystal structure of five tandem Pa 42PRs to 1.6 A, and examined the stability and solution properties of constructs containing three to six Pa 42PRs. Compared with 34-residue TPRs (34PRs), Pa 42PRs have a one-turn extension of each helix, and bury more surface area. Unfolding transitions shift to higher denaturant concentration and become sharper as repeats are added. Fitted Ising models show Pa 42PRs to be more cooperative than consensus 34PRs, with increased magnitudes of intrinsic and interfacial free energies. These results demonstrate the tolerance of the TPR motif to length variation, and provide a basis to understand the effects of helix length on intrinsic/interfacial stability.
PDB ID: 4Y6WDownload
MMDB ID: 133601
PDB Deposition Date: 2015/2/13
Updated in MMDB: 2015/11
Experimental Method:
x-ray diffraction
Resolution: 1.59  Å
Source Organism:
Similar Structures:
Biological Unit for 4Y6W: dimeric; determined by author and by software (PISA)
Molecular Components in 4Y6W
Label Count Molecule
Proteins (2 molecules)
Nab(ab)3acb - Light Chain Tpr-like Repeats
Molecule annotation
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Citing MMDB