Folding mechanism of ribonuclease T1 in the absence of the disulfide bonds.


Abstract

In the absence of its two disulfide bonds, ribonuclease T1 can exist in a native-like folded conformation when > or = 2 M NaCl is present. We measured the kinetics of unfolding and refolding of two reduced and carboxymethylated variants of ribonuclease T1 with one cis proline (the Ser54Gly/Pro55Asn variant) and with two cis prolines (the wild-type protein) as a function of the NaCl concentration. Single and double mixing techniques were used. Analysis of the kinetic results demonstrates that the two cis prolyl bonds at Pro39 and Pro55 remain cis in the folded state after the reduction and carboxymethylation of the disulfide bonds. Folded molecules with trans isomers could not be found. The substitution of cis-Pro55 influences the proline-limited folding reaction, and the analysis of the changes in the folding kinetics shows that the trans-->cis isomerizations of both prolines are slow and are rate-determining steps for the refolding of ribonuclease T1 in the presence as well as in the absence of the disulfide bonds. The direct folding reaction of protein chains with correct prolyl isomers is also affected by the Ser54Gly/Pro55Asn mutation. The rate of refolding is decreased, whereas the rate of unfolding is almost unaffected. The kinetic analysis points to two main consequences of the Ser54Gly/Pro55Asn mutation for the stability and the folding mechanism of RNase T1. It is moderately destabilizing, because the deletion of a conformationally restricted residue (Pro55-->Asn) and the insertion of a flexible residue (Ser54-->Gly) both tend to increase the entropy of the unfolded state. The cis<-->trans isomerization of Pro55 is abolished, however, leading to a decrease in the entropy of the unfolded protein. These two entropic contributions seem to partially compensate each other, and the net change in free energy as a consequence of the Ser54Gly/Pro55Asn double mutation is very small. Study holds ProTherm entries: 4527, 4528 Extra Details: measurements were made in the absence of disulfide bonds disulfide bonds; cis prolines; reduction; carboxymethylation;,cis<-->trans isomerization; entropic contributions

Submission Details

ID: JhRDLJPX3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:26 p.m.

Version: 1

Publication Details
Mücke M;Schmid FX,Biochemistry (1994) Folding mechanism of ribonuclease T1 in the absence of the disulfide bonds. PMID:7981223
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
1IYY 2003-10-07 NMR STRUCTURE OF Gln25-RIBONUCLEASE T1, 24 STRUCTURES
1YGW 1997-10-08 NMR STRUCTURE OF RIBONUCLEASE T1, 34 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
1LOY 2002-08-21 1.55 X-ray structure of the H40A/E58A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
1LOV 2002-08-21 1.55 X-ray structure of the E58A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
4GSP 1998-08-12 1.65 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS + 3'-GMP, 7 DAYS
1I0X 2001-02-14 1.65 RIBONUCLEASE T1 IN COMPLEX WITH 2'GMP (FORM II CRYSTAL)
1RGA 1993-10-31 1.7 CRYSTAL STRUCTURE OF RNASE T1 WITH 3'-GMP AND GUANOSINE: A PRODUCT COMPLEX
4BIR 1998-07-15 1.7 RIBONUCLEASE T1: FREE HIS92GLN MUTANT
1Q9E 2004-03-23 1.7 RNase T1 variant with adenine specificity
1HYF 2001-02-14 1.7 RIBONUCLEASE T1 V16A MUTANT IN COMPLEX WITH SR2+
1I3I 2001-03-07 1.76 Ribonuclease T1 V78T mutant
3BU4 1998-09-23 1.77 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
5BU4 1998-09-23 1.77 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
1RN4 1993-01-15 1.8 HIS92ALA MUTATION IN RIBONUCLEASE T1 INDUCES SEGMENTAL FLEXIBILITY. AN X-RAY STUDY
1DET 1996-07-11 1.8 RIBONUCLEASE T1 CARBOXYMETHYLATED AT GLU 58 IN COMPLEX WITH 2'GMP
5GSP 1998-03-18 1.8 RIBONUCLEASE T1/3'-GMP, 9 WEEKS
1BIR 1996-08-17 1.8 RIBONUCLEASE T1, PHE 100 TO ALA MUTANT COMPLEXED WITH 2' GMP
3BIR 1997-12-31 1.8 DISECTING HISTIDINE INTERACTIONS IN RIBONUCLEASE T1 BY ASN AND GLN SUBSTITUTIONS
1I2E 2001-03-07 1.8 Ribonuclease T1 V16A mutant, form I
2GSP 1998-08-12 1.8 RIBONUCLEASE T1/2',3'-CGPS AND 3'-GMP, 2 DAYS
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
6RNT 1993-01-15 1.8 CRYSTAL STRUCTURE OF RIBONUCLEASE T1 COMPLEXED WITH ADENOSINE 2'-MONOPHOSPHATE AT 1.8-ANGSTROMS RESOLUTION
8RNT 1993-01-15 1.8 STRUCTURE OF RIBONUCLEASE T1 COMPLEXED WITH ZINC(II) AT 1.8 ANGSTROMS RESOLUTION: A ZN2+.6H2O.CARBOXYLATE CLATHRATE
1HZ1 2001-01-31 1.8 RIBONUCLEASE T1 V16A MUTANT IN COMPLEX WITH MG2+
3RNT 1989-10-15 1.8 CRYSTAL STRUCTURE OF GUANOSINE-FREE RIBONUCLEASE T1, COMPLEXED WITH VANADATE(V), SUGGESTS CONFORMATIONAL CHANGE UPON SUBSTRATE BINDING
2AAE 1994-01-31 1.8 THE ROLE OF HISTIDINE-40 IN RIBONUCLEASE T1 CATALYSIS: THREE-DIMENSIONAL STRUCTURES OF THE PARTIALLY ACTIVE HIS40LYS MUTANT
1FZU 2000-10-25 1.8 RNAse T1 V78A mutant
4BU4 1998-09-23 1.8 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
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
2HOH 1998-09-23 1.9 RIBONUCLEASE T1 (N9A MUTANT) COMPLEXED WITH 2'GMP
1BU4 1999-02-16 1.9 RIBONUCLEASE 1 COMPLEX WITH 2'GMP
3GSP 1998-08-12 1.9 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS + 3'-GMP, 4 DAYS
1LOW 2002-08-21 1.9 X-ray structure of the H40A mutant of Ribonuclease T1 complexed with 3'-guanosine monophosphate
1LRA 1994-01-31 1.9 CRYSTALLOGRAPHIC STUDY OF GLU 58 ALA RNASE T1(ASTERISK)2'-GUANOSINE MONOPHOSPHATE AT 1.9 ANGSTROMS RESOLUTION
7RNT 1993-01-15 1.9 CRYSTAL STRUCTURE OF THE TYR45TRP MUTANT OF RIBONUCLEASE T1 IN A COMPLEX WITH 2'-ADENYLIC ACID
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
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
1BVI 1998-09-23 1.9 RIBONUCLEASE T1 (WILDTYPE) COMPLEXED 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
1RHL 1998-10-14 1.95 RIBONUCLEASE T1 COMPLEXED WITH 2'GMP/G23A MUTANT
2BU4 1998-09-23 1.95 RIBONUCLEASE T1 COMPLEX WITH 2'GMP
3SYU 2012-03-28 1.95 Re-refined coordinates for pdb entry 1det - ribonuclease T1 carboxymethylated at GLU 58 in complex with 2'GMP
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.
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
1FYS 2000-10-25 2.0 Ribonuclease T1 V16C mutant
7GSP 1998-03-18 2.0 RIBONUCLEASE T1/2',3'-CGPS, NON-PRODUCTIVE
5HOH 1998-09-23 2.0 RIBONUCLEASE T1 (ASN9ALA/THR93ALA DOUBLEMUTANT) COMPLEXED WITH 2'GMP
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
5BIR 1997-12-31 2.0 DISECTING HISTIDINE INTERACTIONS IN RIBONUCLEASE T1 USING ASN AND GLN MUTATIONS
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
1GSP 1998-02-25 2.2 RIBONUCLEASE T1 COMPLEXED WITH 2',3'-CGPS, 1 DAY
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
1CH0 1999-12-22 2.3 RNASE T1 VARIANT WITH ALTERED GUANINE BINDING SEGMENT
2BIR 1997-06-16 2.3 ADDITIVITY OF SUBSTRATE BINDING IN RIBONUCLEASE T1 (Y42A MUTANT)
1TRQ 1994-04-30 2.3 X-RAY CRYSTALLOGRAPHIC AND CALORIMERIC STUDIES OF THE EFFECTS OF THE MUTATION TRP 59 TYR IN RIBONUCLEASE T1
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