title: Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA.
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.
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
authors.forename: Yu-Yung
authors.initials: YY
authors.lastname: Chang
authors.affiliation: 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.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Hsu
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D002942:Circular Dichroism; D006860:Hydrogen Bonding; D016297:Mutagenesis, Site-Directed; D063209:N-Terminal Acetyltransferase A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D048229:Sulfolobus solfataricus / Q000378:metabolism; D013816:Thermodynamics; D044366:Transition Temperature
chemical_list: D019843:Archaeal Proteins; D063209:N-Terminal Acetyltransferase A
keywords: acetyltransferase; biophysics; crystallization; enzymes; thermostability