Structure of a rapidly formed intermediate in ribonuclease T1 folding.


Abstract

Kinetic intermediates in protein folding are short-lived and therefore difficult to detect and to characterize. In the folding of polypeptide chains with incorrect isomers of Xaa-Pro peptide bonds the final rate-limiting transition to the native state is slow, since it is coupled to prolyl isomerization. Incorrect prolyl isomers thus act as effective traps for folding intermediates and allow their properties to be studied more easily. We employed this strategy to investigate the mechanism of slow folding of ribonuclease T1. In our experiments we use a mutant form of this protein with a single cis peptide bond at proline 39. During refolding, protein chains with an incorrect trans proline 39 can rapidly form extensive secondary structure. The CD signal in the amide region is regained within the dead-time of stopped-flow mixing (15 ms), indicating a fast formation of the single alpha-helix of ribonuclease T1. This step is correlated with partial formation of a hydrophobic core, because the fluorescence emission maximum of tryptophan 59 is shifted from 349 nm to 325 nm within less than a second. After about 20 s of refolding an intermediate is present that shows about 40% enzymatic activity compared to the completely refolded protein. In addition, the solvent accessibility of tryptophan 59 is drastically reduced in this intermediate and comparable to that of the native state as determined by acrylamide quenching of the tryptophan fluorescence. Activity and quenching measurements have long dead-times and therefore we do not know whether enzymatic activity and solvent accessibility also change in the time range of milliseconds. At this stage of folding at least part of the beta-sheet structure is already present, since it hosts the active site of the enzyme. The trans to cis isomerization of the tyrosine 38-proline 39 peptide bond in the intermediate and consequently the formation of native protein is very slow (tau = 6,500 s at pH 5.0 and 10 degrees C). It is accompanied by an additional increase in tryptophan fluorescence, by the development of the fine structure of the tryptophan emission spectrum, and by the regain of the full enzymatic activity. This indicates that the packing of the hydrophobic core, which involves both tryptophan 59 and proline 39, is optimized in this step. Apparently, refolding polypeptide chains with an incorrect prolyl isomer can very rapidly form partially folded intermediates with native-like properties. Study holds ProTherm entries: 10998 Extra Details:

Submission Details

ID: xg2JvGis3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:41 p.m.

Version: 1

Publication Details
Kiefhaber T;Schmid FX;Willaert K;Engelborghs Y;Chaffotte A,Protein Sci. (1992) Structure of a rapidly formed intermediate in ribonuclease T1 folding. PMID:1304394
Additional Information

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 PDB Entries

Structure ID Release Date Resolution Structure Title
1YGW 1997-10-08 NMR STRUCTURE OF RIBONUCLEASE T1, 34 STRUCTURES
1IYY 2003-10-07 NMR STRUCTURE OF Gln25-RIBONUCLEASE T1, 24 STRUCTURES
1I0V 2001-02-14 1.23 Ribonuclease T1 in complex with 2'GMP (form I crystal)
4ODK 2015-01-14 1.4 Structure of SlyD from Thermus thermophilus in complex with T1 peptide
9RNT 1993-01-15 1.5 RIBONUCLEASE T1 WITH FREE RECOGNITION AND CATALYTIC SITE: CRYSTAL STRUCTURE ANALYSIS AT 1.5 ANGSTROMS RESOLUTION
1LOV 2002-08-21 1.55 X-ray structure of the E58A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
1LOY 2002-08-21 1.55 X-ray structure of the H40A/E58A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
1I0X 2001-02-14 1.65 RIBONUCLEASE T1 IN COMPLEX WITH 2'GMP (FORM II CRYSTAL)
4GSP 1998-08-12 1.65 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS + 3'-GMP, 7 DAYS
1HYF 2001-02-14 1.7 RIBONUCLEASE T1 V16A MUTANT IN COMPLEX WITH SR2+
4BIR 1998-07-15 1.7 RIBONUCLEASE T1: FREE HIS92GLN MUTANT
1Q9E 2004-03-23 1.7 RNase T1 variant with adenine specificity
1RGA 1993-10-31 1.7 CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX
1I3I 2001-03-07 1.76 Ribonuclease T1 V78T mutant
5BU4 1998-09-23 1.77 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
3BU4 1998-09-23 1.77 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
3RNT 1989-10-15 1.8 CRYSTAL STRUCTURE OF GUANOSINE-FREE RIBONUCLEASE T1, COMPLEXED WITH VANADATE(V), SUGGESTS CONFORMATIONAL CHANGE UPON SUBSTRATE BINDING
1BIR 1996-08-17 1.8 RIBONUCLEASE T1, PHE 100 TO ALA MUTANT COMPLEXED WITH 2' GMP
1RN4 1993-01-15 1.8 HIS92ALA MUTATION IN RIBONUCLEASE T1 INDUCES SEGMENTAL FLEXIBILITY. AN X-RAY STUDY
2AAE 1994-01-31 1.8 THE ROLE OF HISTIDINE-40 IN RIBONUCLEASE T1 CATALYSIS: THREE-DIMENSIONAL STRUCTURES OF THE PARTIALLY ACTIVE HIS40LYS MUTANT
1I2E 2001-03-07 1.8 Ribonuclease T1 V16A mutant, form I
5GSP 1998-03-18 1.8 RIBONUCLEASE T1/3'-GMP, 9 WEEKS
3BIR 1997-12-31 1.8 DISECTING HISTIDINE INTERACTIONS IN RIBONUCLEASE T1 BY ASN AND GLN SUBSTITUTIONS
8RNT 1993-01-15 1.8 STRUCTURE OF RIBONUCLEASE T1 COMPLEXED WITH ZINC(II) AT 1.8 ANGSTROMS RESOLUTION: A ZN2+.6H2O.CARBOXYLATE CLATHRATE
4BU4 1998-09-23 1.8 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
1FZU 2000-10-25 1.8 RNAse T1 V78A mutant
1HZ1 2001-01-31 1.8 RIBONUCLEASE T1 V16A MUTANT IN COMPLEX WITH MG2+
2RNT 1989-10-15 1.8 THREE-DIMENSIONAL STRUCTURE OF RIBONUCLEASE T1 COMPLEXED WITH GUANYLYL-2(PRIME),5(PRIME)-GUANOSINE AT 1.8 ANGSTROMS RESOLUTION
2GSP 1998-08-12 1.8 RIBONUCLEASE T1/2',3'-CGPS AND 3'-GMP, 2 DAYS
1DET 1996-07-11 1.8 RIBONUCLEASE T1 CARBOXYMETHYLATED AT GLU 58 IN COMPLEX WITH 2'GMP
6RNT 1993-01-15 1.8 CRYSTAL STRUCTURE OF RIBONUCLEASE T1 COMPLEXED WITH ADENOSINE 2'-MONOPHOSPHATE AT 1.8-ANGSTROMS RESOLUTION
1RN1 1994-01-31 1.84 THREE-DIMENSIONAL STRUCTURE OF GLN 25-RIBONUCLEASE T1 AT 1.84 ANGSTROMS RESOLUTION: STRUCTURAL VARIATIONS AT THE BASE RECOGNITION AND CATALYTIC SITES
1I2G 2001-03-07 1.85 Ribonuclease T1 V16T mutant
1G02 2000-10-25 1.86 Ribonuclease T1 V16S mutant
1RGK 1993-01-15 1.87 RNASE T1 MUTANT GLU46GLN BINDS THE INHIBITORS 2'GMP AND 2'AMP AT THE 3' SUBSITE
3GSP 1998-08-12 1.9 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS + 3'-GMP, 4 DAYS
1RLS 1994-12-20 1.9 CRYSTAL STRUCTURE OF RNASE T1 COMPLEXED WITH THE PRODUCT NUCLEOTIDE 3'-GMP. STRUCTURAL EVIDENCE FOR DIRECT INTERACTION OF HISTIDINE 40 AND GLUTAMIC ACID 58 WITH THE 2'-HYDROXYL GROUP OF RIBOSE
1LRA 1994-01-31 1.9 CRYSTALLOGRAPHIC STUDY OF GLU 58 ALA RNASE T1(ASTERISK)2'-GUANOSINE MONOPHOSPHATE AT 1.9 ANGSTROMS RESOLUTION
1LOW 2002-08-21 1.9 X-ray structure of the H40A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
1BU4 1999-02-16 1.9 RIBONUCLEASE 1 COMPLEX WITH 2'GMP
1RNT 1987-10-16 1.9 RESTRAINED LEAST-SQUARES REFINEMENT OF THE CRYSTAL STRUCTURE OF THE RIBONUCLEASE T1(ASTERISK)2(PRIME)-GUANYLIC ACID COMPLEX AT 1.9 ANGSTROMS RESOLUTION
2HOH 1998-09-23 1.9 RIBONUCLEASE T1 (N9A MUTANT) COMPLEXED WITH 2'GMP
1BVI 1998-09-23 1.9 RIBONUCLEASE T1 (WILDTYPE) COMPLEXED WITH 2'GMP
7RNT 1993-01-15 1.9 CRYSTAL STRUCTURE OF THE TYR45TRP MUTANT OF RIBONUCLEASE T1 IN A COMPLEX WITH 2'-ADENYLIC ACID
1RHL 1998-10-14 1.95 RIBONUCLEASE T1 COMPLEXED WITH 2'GMP/G23A MUTANT
3SYU 2012-03-28 1.95 Re-refined coordinates for pdb entry 1det - ribonuclease T1 carboxymethylated at GLU 58 in complex with 2'GMP
2BU4 1998-09-23 1.95 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
3HOH 1998-09-16 1.95 RIBONUCLEASE T1 (THR93GLN MUTANT) COMPLEXED WITH 2'GMP
1I2F 2001-03-07 1.95 Ribonuclease T1 V16A mutant, form II
1RGC 1994-01-31 2.0 THE COMPLEX BETWEEN RIBONUCLEASE T1 AND 3'-GUANYLIC ACID SUGGESTS GEOMETRY OF ENZYMATIC REACTION PATH. AN X-RAY STUDY
5HOH 1998-09-23 2.0 RIBONUCLEASE T1 (ASN9ALA/THR93ALA DOUBLEMUTANT) COMPLEXED WITH 2'GMP
2AAD 1994-01-31 2.0 THE ROLE OF HISTIDINE-40 IN RIBONUCLEASE T1 CATALYSIS: THREE-DIMENSIONAL STRUCTURES OF THE PARTIALLY ACTIVE HIS40LYS MUTANT
1RGL 1993-01-15 2.0 RNASE T1 MUTANT GLU46GLN BINDS THE INHIBITORS 2'GMP AND 2'AMP AT THE 3' SUBSITE
1B2M 1999-03-25 2.0 THREE-DIMENSIONAL STRUCTURE OF RIBONULCEASE T1 COMPLEXED WITH AN ISOSTERIC PHOSPHONATE ANALOGUE OF GPU: ALTERNATE SUBSTRATE BINDING MODES AND CATALYSIS.
5BIR 1997-12-31 2.0 DISECTING HISTIDINE INTERACTIONS IN RIBONUCLEASE T1 USING ASN AND GLN MUTATIONS
7GSP 1998-03-18 2.0 RIBONUCLEASE T1/2',3'-CGPS, NON-PRODUCTIVE
1FYS 2000-10-25 2.0 Ribonuclease T1 V16C mutant
4HOH 1998-09-23 2.05 RIBONUCLEASE T1 (THR93ALA MUTANT) COMPLEXED WITH 2'GMP
1TTO 2005-09-06 2.1 Crystal structure of the Rnase T1 variant R2
4RNT 1992-01-15 2.2 HIS 92 ALA MUTATION IN RIBONUCLEASE T1 INDUCES SEGMENTAL FLEXIBILITY. AN X-RAY STUDY
6GSP 1998-03-18 2.2 RIBONUCLEASE T1/3'-GMP, 15 WEEKS
1GSP 1998-02-25 2.2 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS, 1 DAY
1CH0 1999-12-22 2.3 RNASE T1 VARIANT WITH ALTERED GUANINE BINDING SEGMENT
1TRQ 1994-04-30 2.3 X-RAY CRYSTALLOGRAPHIC AND CALORIMERIC STUDIES OF THE EFFECTS OF THE MUTATION TRP 59 TYR IN RIBONUCLEASE T1
2BIR 1997-06-16 2.3 ADDITIVITY OF SUBSTRATE BINDING IN RIBONUCLEASE T1 (Y42A MUTANT)
1I3F 2001-03-07 2.35 Ribonuclease T1 V89S mutant
1TRP 1994-04-30 2.4 X-RAY CRYSTALLOGRAPHIC AND CALORIMERIC STUDIES OF THE EFFECTS OF THE MUTATION TRP 59 TYR IN RIBONUCLEASE T1
3URP 2012-03-28 3.19 Re-refinement of PDB entry 5RNT - ribonuclease T1 with guanosine-3',5'-diphosphate and phosphate ion bound
5RNT 1993-01-15 3.2 X-RAY ANALYSIS OF CUBIC CRYSTALS OF THE COMPLEX FORMED BETWEEN RIBONUCLEASE T1 AND GUANOSINE-3',5'-BISPHOSPHATE

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Guanyl-specific ribonuclease T1 P00651 RNT1_ASPOR