%0 Journal Article
%@ 2045-2322
%A Sharma, Pankaj
%A Tomar, Rachana
%A Yadav, Shiv Pratap Singh
%A Badmalia, Maulik D
%A Nath, Samir K
%A Ashish, .
%A Kundu, Bishwajit
%D 2020
%F open:2634
%I Nature publishing group
%J Scientific reports
%K Biophysics, Structural biology
%T Heat induces end to end repetitive association in P. furiosusl-asparaginase which enables its thermophilic property
%U http://crdd.osdd.net/open/2634/
%V 10
%X It remains undeciphered how thermophilic enzymes display enhanced stability at elevated temperatures. Taking l-asparaginase from P. furiosus (PfA) as an example, we combined scattering shapes deduced from small-angle X-ray scattering (SAXS) data at increased temperatures with symmetry mates from crystallographic structures to find that heating caused end-to-end association. The small contact point of self-binding appeared to be enabled by a terminal short β-strand in N-terminal domain, Leu179-Val-Val-Asn182 (LVVN). Interestingly, deletion of this strand led to a defunct enzyme, whereas suplementation of the peptide LVVN to the defunct enzyme restored structural frameworkwith mesophile-type functionality. Crystal structure of the peptide-bound defunct enzyme showed that one peptide ispresent in the same coordinates as in original enzyme, explaining gain-of lost function. A second peptide was seen bound to the protein at a different location suggesting its possible role in substrate-free molecular-association. Overall, we show that the heating induced self-assembly of native shapes of PfA led to an apparent super-stable assembly.
%Z Open Access