Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA.
Chang, Y.Y., Hsu, C.H.(2016) Chembiochem 17: 214-217
- PubMed: 26593285 
- DOI: https://doi.org/10.1002/cbic.201500568
- Primary Citation of Related Structures:  
5C88 - PubMed 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.
Organizational Affiliation: 
Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.