Abstract
The Arginine Binding Protein isolated from Thermotoga maritima (TmArgBP) is a protein endowed with several peculiar properties. We have previously shown that TmArgBP dimerization is a consequence of the swapping of the C-terminal helix. Here we explored the structural determinants of TmArgBP domain swapping and oligomerization. In particular, we report a mutational analysis of the residue Pro235, which is located in the hinge region of the swapping dimer. This residue was either replaced with a Gly-Lys dipeptide (TmArgBPP235GK) or a Gly residue (TmArgBPP235G). Different forms of these mutants were generated and extensively characterized using biophysical techniques. For both TmArgBPP235GK and TmArgBPP235G mutants, the occurrence of multiple oligomerization states (monomers, dimers and trimers) was detected. The formation of well-folded monomeric forms for these mutants indicates that the dimerization through C-terminal domain swapping observed in wild-type TmArgBP is driven by conformational restraints imposed by the presence of Pro235 in the hinge region. Molecular dynamics studies corroborate this observation by showing that Gly235 assumes conformational states forbidden for Pro residues in the TmArgBPP235G monomer. Unexpectedly, the trimeric forms present: (a) peculiar circular dichroism spectra, (b) a great susceptibility to heating, and (c) the ability to bind the Thioflavin T dye. The present findings clearly demonstrate that single-point mutations have an important impact on the TmArgBP oligomerization process. In a wider context, they also indicate that proteins endowed with an intrinsic propensity to swap have an easy access to states with altered structural and, possibly, functional properties.
| Original language | English |
|---|---|
| Pages (from-to) | 814-824 |
| Number of pages | 11 |
| Journal | Biochimica et Biophysica Acta - Proteins and Proteomics |
| Volume | 1864 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Jul 1 2016 |
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Keywords
- Differential scanning calorimetry
- Domain swapping
- Protein oligomerization
- Protein structure dynamics
- Protein structure-stability
ASJC Scopus subject areas
- Analytical Chemistry
- Biophysics
- Biochemistry
- Molecular Biology
Cite this
Proline 235 plays a key role in the regulation of the oligomeric states of Thermotoga maritima Arginine Binding Protein. / Smaldone, Giovanni; Vigorita, Marilisa; Ruggiero, Alessia; Balasco, Nicole; Dattelbaum, Jonathan D.; D'Auria, Sabato; Del Vecchio, Pompea; Graziano, Giuseppe; Vitagliano, Luigi.
In: Biochimica et Biophysica Acta - Proteins and Proteomics, Vol. 1864, No. 7, 01.07.2016, p. 814-824.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Proline 235 plays a key role in the regulation of the oligomeric states of Thermotoga maritima Arginine Binding Protein
AU - Smaldone, Giovanni
AU - Vigorita, Marilisa
AU - Ruggiero, Alessia
AU - Balasco, Nicole
AU - Dattelbaum, Jonathan D.
AU - D'Auria, Sabato
AU - Del Vecchio, Pompea
AU - Graziano, Giuseppe
AU - Vitagliano, Luigi
PY - 2016/7/1
Y1 - 2016/7/1
N2 - The Arginine Binding Protein isolated from Thermotoga maritima (TmArgBP) is a protein endowed with several peculiar properties. We have previously shown that TmArgBP dimerization is a consequence of the swapping of the C-terminal helix. Here we explored the structural determinants of TmArgBP domain swapping and oligomerization. In particular, we report a mutational analysis of the residue Pro235, which is located in the hinge region of the swapping dimer. This residue was either replaced with a Gly-Lys dipeptide (TmArgBPP235GK) or a Gly residue (TmArgBPP235G). Different forms of these mutants were generated and extensively characterized using biophysical techniques. For both TmArgBPP235GK and TmArgBPP235G mutants, the occurrence of multiple oligomerization states (monomers, dimers and trimers) was detected. The formation of well-folded monomeric forms for these mutants indicates that the dimerization through C-terminal domain swapping observed in wild-type TmArgBP is driven by conformational restraints imposed by the presence of Pro235 in the hinge region. Molecular dynamics studies corroborate this observation by showing that Gly235 assumes conformational states forbidden for Pro residues in the TmArgBPP235G monomer. Unexpectedly, the trimeric forms present: (a) peculiar circular dichroism spectra, (b) a great susceptibility to heating, and (c) the ability to bind the Thioflavin T dye. The present findings clearly demonstrate that single-point mutations have an important impact on the TmArgBP oligomerization process. In a wider context, they also indicate that proteins endowed with an intrinsic propensity to swap have an easy access to states with altered structural and, possibly, functional properties.
AB - The Arginine Binding Protein isolated from Thermotoga maritima (TmArgBP) is a protein endowed with several peculiar properties. We have previously shown that TmArgBP dimerization is a consequence of the swapping of the C-terminal helix. Here we explored the structural determinants of TmArgBP domain swapping and oligomerization. In particular, we report a mutational analysis of the residue Pro235, which is located in the hinge region of the swapping dimer. This residue was either replaced with a Gly-Lys dipeptide (TmArgBPP235GK) or a Gly residue (TmArgBPP235G). Different forms of these mutants were generated and extensively characterized using biophysical techniques. For both TmArgBPP235GK and TmArgBPP235G mutants, the occurrence of multiple oligomerization states (monomers, dimers and trimers) was detected. The formation of well-folded monomeric forms for these mutants indicates that the dimerization through C-terminal domain swapping observed in wild-type TmArgBP is driven by conformational restraints imposed by the presence of Pro235 in the hinge region. Molecular dynamics studies corroborate this observation by showing that Gly235 assumes conformational states forbidden for Pro residues in the TmArgBPP235G monomer. Unexpectedly, the trimeric forms present: (a) peculiar circular dichroism spectra, (b) a great susceptibility to heating, and (c) the ability to bind the Thioflavin T dye. The present findings clearly demonstrate that single-point mutations have an important impact on the TmArgBP oligomerization process. In a wider context, they also indicate that proteins endowed with an intrinsic propensity to swap have an easy access to states with altered structural and, possibly, functional properties.
KW - Differential scanning calorimetry
KW - Domain swapping
KW - Protein oligomerization
KW - Protein structure dynamics
KW - Protein structure-stability
UR - http://www.scopus.com/inward/record.url?scp=84964320753&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84964320753&partnerID=8YFLogxK
U2 - 10.1016/j.bbapap.2016.04.006
DO - 10.1016/j.bbapap.2016.04.006
M3 - Article
C2 - 27087545
AN - SCOPUS:84964320753
VL - 1864
SP - 814
EP - 824
JO - Biochimica et Biophysica Acta - Proteins and Proteomics
JF - Biochimica et Biophysica Acta - Proteins and Proteomics
SN - 1570-9639
IS - 7
ER -