Amino acid replacements can selectively affect the interaction energy of autonomous folding units in the alpha subunit of tryptophan synthase.

Abstract

Amino acid replacements were made at the interface between two autonomous folding units in the alpha subunit of tryptophan synthase from Salmonella typhimurium to test their mutual interaction energy. The results of equilibrium studies of the urea-induced unfolding reaction of the wild-type and mutant proteins in which phenylalanine 22 is replaced by leucine, isoleucine, and valine can be understood in terms of a selective decrease in the interaction energy between the two folding units; the intrinsic stability of each folding unit is not significantly altered. Kinetic studies of the rate-limiting step in unfolding show that the interaction energy appears in the transition state preceding the native conformation. Comparisons of the individual effects of these nonpolar side chains show that both hydrophobic and steric effects play important roles in the interaction energy between the folding units. The implication of these results is that the high cooperativity observed in the folding of many globular proteins may be reduced by appropriate amino acid replacements. Study holds ProTherm entries: 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247 Extra Details: additive : K2EDTA(5 mM), alpha subunit of tryptophan synthase; interaction energy;,hydrophobic; amino acid replacements

Submission Details

ID: DuJphBqK3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:14 p.m.

Version: 1

Publication Details
Chen X;Rambo R;Matthews CR,Biochemistry (1992) Amino acid replacements can selectively affect the interaction energy of autonomous folding units in the alpha subunit of tryptophan synthase. PMID:1540577
Additional Information

Study Summary

Number of data points 37
Proteins Tryptophan synthase alpha chain ; Tryptophan synthase alpha chain
Unique complexes 4
Assays/Quantities/Protocols Experimental Assay: Cm ; Experimental Assay: m ; Experimental Assay: dG_H2O ; Derived Quantity: ddG_H2O
Libraries Mutations for sequence A:MERYENLFAQLNDRREGAFVPFVTLGDPGIEQSLKIIDTLIDAGADALELGVPFSDPLADGPTIQNANLRAFAAGVTPAQCFEMLALIREKHPTIPIGLLMYANLVFNNGIDAFYARCEQVGVDSVLVADVPVEESAPFRQAALRHNIAPIFICPPNADDDLLRQVASYGRGYTYLLSRSGVTGAENRGALPLHHLIEKLKEYHAAPALQGFGISSPEQVSAAVRAGAAGAISGSAIVKIIEKNLASPKQMLAELRSFVSAMKAASRA/B:TTLLNPYFGEFGGMYVPQILMPALNQLEEAFVRAQKDPEFQAQFADLLKNYAGRPTALTKCQNITAGTRTTLYLKREDLLHGGAHKTNQVLGQALLAKRMGKSEIIAETGAGQHGVASALASALLGLKCRIYMGAKDVERQSPNVFRMRLMGAEVIPVHSGSATLKDACNEALRDWSGSYETAHYMLGTAAGPHPYPTIVREFQRMIGEETKAQILDKEGRLPDAVIACVGGGSNAIGMFADFINDTSVGLIGVEPGGHGIETGEHGAPLKHGRVGIYFGMKAPMMQTADGQIEESYSISAGLDFPSVGPQHAYLNSIGRADYVSITDDEALEAFKTLCRHEGIIPALESSHALAHALKMMREQPEKEQLLVVNLSGRGDKDIFTVHDILKARGEI

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Tryptophan synthase alpha chain P00929 TRPA_SALTY
99.6 Tryptophan synthase alpha chain B5F4M3 TRPA_SALA4
99.6 Tryptophan synthase alpha chain B5FU65 TRPA_SALDC
99.6 Tryptophan synthase alpha chain B5R3P3 TRPA_SALEP
99.6 Tryptophan synthase alpha chain B5R6M4 TRPA_SALG2
99.6 Tryptophan synthase alpha chain B4TJK9 TRPA_SALHS
99.6 Tryptophan synthase alpha chain B4T6X2 TRPA_SALNS
99.6 Tryptophan synthase alpha chain A9MWR3 TRPA_SALPB
99.6 Tryptophan synthase alpha chain Q8Z7E0 TRPA_SALTI
99.3 Tryptophan synthase alpha chain Q57NT2 TRPA_SALCH
99.3 Tryptophan synthase alpha chain C0Q3N3 TRPA_SALPC
99.3 Tryptophan synthase alpha chain Q5PNM0 TRPA_SALPA
99.3 Tryptophan synthase alpha chain B5BIC0 TRPA_SALPK
98.9 Tryptophan synthase alpha chain B4TX39 TRPA_SALSV
95.1 Tryptophan synthase alpha chain A9MPY6 TRPA_SALAR
99.7 B Tryptophan synthase alpha chain B5F4M4 TRPB_SALA4
99.7 B Tryptophan synthase alpha chain B5FU66 TRPB_SALDC
99.7 B Tryptophan synthase alpha chain B5R3P4 TRPB_SALEP
99.7 B Tryptophan synthase alpha chain B5R6M5 TRPB_SALG2
99.7 B Tryptophan synthase alpha chain B4TJK8 TRPB_SALHS
99.7 B Tryptophan synthase alpha chain B4T6X1 TRPB_SALNS
99.7 B Tryptophan synthase alpha chain Q5PD17 TRPB_SALPA
99.7 B Tryptophan synthase alpha chain A9MWR4 TRPB_SALPB
99.7 B Tryptophan synthase alpha chain C0Q3N4 TRPB_SALPC
99.7 B Tryptophan synthase alpha chain B5BIC1 TRPB_SALPK
99.7 B Tryptophan synthase alpha chain B4TX38 TRPB_SALSV
99.7 B Tryptophan synthase alpha chain P0A2K2 TRPB_SALTI
99.7 B Tryptophan synthase alpha chain P0A2K1 TRPB_SALTY
99.5 B Tryptophan synthase alpha chain Q57NT3 TRPB_SALCH
98.2 B Tryptophan synthase alpha chain A9MPY7 TRPB_SALAR
96.7 B Tryptophan synthase alpha chain A8AG61 TRPB_CITK8
97.0 B Tryptophan synthase alpha chain B7LS19 TRPB_ESCF3
96.7 B Tryptophan synthase alpha chain Q8X7B6 TRPB_ECO57
96.7 B Tryptophan synthase alpha chain B5YZP1 TRPB_ECO5E
96.7 B Tryptophan synthase alpha chain Q3Z109 TRPB_SHISS
96.7 B Tryptophan synthase alpha chain B7UR67 TRPB_ECO27
96.7 B Tryptophan synthase alpha chain B7NVN1 TRPB_ECO7I
96.7 B Tryptophan synthase alpha chain B7MUA0 TRPB_ECO81
96.7 B Tryptophan synthase alpha chain Q0TIA9 TRPB_ECOL5
96.7 B Tryptophan synthase alpha chain Q8FHV9 TRPB_ECOL6
96.7 B Tryptophan synthase alpha chain B1LH31 TRPB_ECOSM
96.7 B Tryptophan synthase alpha chain Q32GS9 TRPB_SHIDS
96.5 B Tryptophan synthase alpha chain A7ZL79 TRPB_ECO24
96.5 B Tryptophan synthase alpha chain B7L493 TRPB_ECO55
96.5 B Tryptophan synthase alpha chain B7LY17 TRPB_ECO8A
96.5 B Tryptophan synthase alpha chain B1XBL0 TRPB_ECODH
96.5 B Tryptophan synthase alpha chain A7ZZJ7 TRPB_ECOHS
96.5 B Tryptophan synthase alpha chain B1ITJ4 TRPB_ECOLC
96.5 B Tryptophan synthase alpha chain P0A879 TRPB_ECOLI
96.5 B Tryptophan synthase alpha chain B6I9X5 TRPB_ECOSE
96.5 B Tryptophan synthase alpha chain Q0T5D5 TRPB_SHIF8
96.5 B Tryptophan synthase alpha chain P0A880 TRPB_SHIFL
96.5 B Tryptophan synthase alpha chain B7ML77 TRPB_ECO45
96.5 B Tryptophan synthase alpha chain A1AAN1 TRPB_ECOK1
96.5 B Tryptophan synthase alpha chain Q1RCA6 TRPB_ECOUT
96.5 B Tryptophan synthase alpha chain B7N474 TRPB_ECOLU
96.5 B Tryptophan synthase alpha chain B2U0F2 TRPB_SHIB3
96.5 B Tryptophan synthase alpha chain Q31ZV4 TRPB_SHIBS
93.7 B Tryptophan synthase alpha chain B5XT02 TRPB_KLEP3
93.7 B Tryptophan synthase alpha chain A6T7W6 TRPB_KLEP7
92.7 B Tryptophan synthase alpha chain A4WB02 TRPB_ENT38
93.2 B Tryptophan synthase alpha chain A7MMG1 TRPB_CROS8
91.6 B Tryptophan synthase alpha chain C6DGZ5 TRPB_PECCP
91.1 B Tryptophan synthase alpha chain A8GF82 TRPB_SERP5
90.9 B Tryptophan synthase alpha chain Q6D4U0 TRPB_PECAS
90.1 B Tryptophan synthase alpha chain B2VKT2 TRPB_ERWT9