Abstract

The stabilities of 66 sequence variants of the human Pin1 WW domain have been determined by equilibrium thermal denaturation experiments. All 34 residues composing the hPin1 WW three-stranded beta-sheet structure could be replaced one at a time with at least one different natural or non-natural amino acid residue without leading to an unfolded protein. Alanine substitutions at only four positions within the hPin1 WW domain lead to a partially or completely unfolded protein-in the absence of a physiological ligand. The side chains of these four residues form a conserved, partially solvent-inaccessible, continuous hydrophobic minicore comprising the N- and C-termini. Ala mutations at five other residues, three of which constitute the ligand binding patch on the concave side of the beta-sheet, significantly destabilize the hPin1 WW domain without leading to an unfolded protein. The remaining mutations affect protein stability only slightly, suggesting that only a small subset of side chain interactions within the hPin1 WW domain are mandatory for acquiring and maintaining a stable, cooperatively folded beta-sheet structure. Study holds ProTherm entries: 25101, 25102, 25103, 25104, 25105, 25106, 25107, 25108, 25109, 25110, 25111, 25112, 25113, 25114, 25115, 25116, 25117, 25118, 25119, 25120, 25121, 25122, 25123, 25124, 25125, 25126, 25127, 25128, 25129, 25130, 25131, 25132, 25133, 25134, 25135, 25136, 25137, 25138, 25139, 25140, 25141, 25142, 25143, 25144, 25145, 25146, 25147, 25148, 25149, 25150, 25151, 25152, 25153, 25154, 25155, 25156, 25157, 25158, 25159, 25160, 25161, 25162, 25163, 25164, 25165, 25166, 25167, 25168, 25169, 25170, 25171, 25172, 25173, 25174, 25175, 25176, 25177, 25178, 25179, 25180, 25181, 25182, 25183, 25184, 25185, 25186, 25187, 25188, 25189, 25190, 25191, 25192, 25193, 25194, 25195, 25196, 25197, 25198, 25199, 25200, 25201, 25202, 25203, 25204, 25205, 25206, 25207, 25208, 25209, 25210, 25211, 25212, 25213, 25214 Extra Details: WW domain; Ala scanning; Gly scanning; side chain mutagenesis; protein stability; protein folding; beta-sheet

Submission Details

ID: xT7jFTKE4

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:55 p.m.

Version: 1

Publication Details

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