Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA

Yu-Yung Chang; Chun-Hua Hsu

doi:10.1002/cbic.201500568

Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA

Chembiochem. 2016 Feb 2;17(3):214-7. doi: 10.1002/cbic.201500568. Epub 2015 Dec 10.

Authors

Yu-Yung Chang¹, Chun-Hua Hsu²

Affiliations

¹ Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
² Department of Agricultural Chemistry, Center for Systems Biology, Genome and Systems Biology Degree Program, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan. andyhsu@ntu.edu.tw.

PMID: 26593285
DOI: 10.1002/cbic.201500568

Abstract

Structural comparison indicates that the loop region between β3 and β4 of SsArd1 is extended relative to the corresponding region in mesophilic Nats, and forms a plastic hydrogen-bond network mainly at two serine residues. Strikingly, two single-point mutants showed ∼3 °C decrease in melting temperature, and two other variants showed ∼7 °C decrease; this correlated with significantly reduced enzymatic activity. To our knowledge, this is the first discovery of a loop region capable of remarkably improving protein thermostability. This provides a novel route to engineer heat-resistant proteins.

Keywords: acetyltransferase; biophysics; crystallization; enzymes; thermostability.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Archaeal Proteins / chemistry
Archaeal Proteins / genetics
Archaeal Proteins / metabolism*
Biocatalysis
Circular Dichroism
Hydrogen Bonding
Mutagenesis, Site-Directed
N-Terminal Acetyltransferase A / chemistry
N-Terminal Acetyltransferase A / genetics
N-Terminal Acetyltransferase A / metabolism*
Protein Structure, Secondary
Protein Structure, Tertiary
Sulfolobus solfataricus / metabolism
Thermodynamics
Transition Temperature

Substances

Archaeal Proteins
N-Terminal Acetyltransferase A