<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chand, Deepak</style></author><author><style face="normal" font="default" size="100%">Panigrahi, Priyabrata</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structure of highly active BSH enzyme with subordinated post-translational excision</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Crystallographica A‐Foundation and Advances</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bile salt hydrolase</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">X-ray crystallography</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAR</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">70</style></volume><pages><style face="normal" font="default" size="100%">C272</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><work-type><style face="normal" font="default" size="100%">Meeting Abstract</style></work-type><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;
</style></custom3><custom4><style face="normal" font="default" size="100%">&lt;p&gt;2.333&lt;/p&gt;
</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Panigrahi, Priyabrata</style></author><author><style face="normal" font="default" size="100%">Chand, Deepak</style></author><author><style face="normal" font="default" size="100%">Mukherji, Ruchira</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sequence and structure-based comparative analysis to assess, identify and improve the thermostability of penicillin G acylases</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Industrial Microbiology &amp; Biotechnology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alkalistable</style></keyword><keyword><style  face="normal" font="default" size="100%">beta-lactam antibiotics</style></keyword><keyword><style  face="normal" font="default" size="100%">Consensus approach</style></keyword><keyword><style  face="normal" font="default" size="100%">Disulfide bridge</style></keyword><keyword><style  face="normal" font="default" size="100%">Ion pairs</style></keyword><keyword><style  face="normal" font="default" size="100%">Penicillin acylase</style></keyword><keyword><style  face="normal" font="default" size="100%">Thermostability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">NOV</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">11</style></number><publisher><style face="normal" font="default" size="100%">SPRINGER HEIDELBERG</style></publisher><pub-location><style face="normal" font="default" size="100%">TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY</style></pub-location><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">1493-1506</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Penicillin acylases are enzymes employed by the pharmaceutical industry for the manufacture of semi-synthetic penicillins. There is a continuous demand for thermostable and alkalophilic enzymes in such applications. We have carried out a computational analysis of known penicillin G acylases (PGAs) in terms of their thermostable nature using various protein-stabilizing factors. While the presence of disulfide bridges was considered initially to screen putative thermostable PGAs from the database, various other factors such as high arginine to lysine ratio, less content of thermolabile amino acids, presence of proline in beta-turns, more number of ion-pair and other non-bonded interactions were also considered for comparison. A modified consensus approach designed could further identify stabilizing residue positions by site-specific comparison between mesostable and thermostable PGAs. A most likely thermostable enzyme identified from the analysis was PGA from Paracoccus denitrificans (PdPGA). This was cloned, expressed and tested for its thermostable nature using biochemical and biophysical experiments. The consensus site-specific sequence-based approach predicted PdPGA to be more thermostable than Escherichia coli PGA, but not as thermostable as the PGA from Achromobacter xylosoxidans. Experimental data showed that PdPGA was comparatively less thermostable than Achromobacter xylosoxidans PGA, although thermostability factors favored a much higher stability. Despite being mesostable, PdPGA being active and stable at alkaline pH is an advantage. Finally, several residue positions could be identified in PdPGA, which upon mutation selectively could improve the thermostability of the enzyme.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">2.745</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chand, Deepak</style></author><author><style face="normal" font="default" size="100%">Varshney, NishantKumar</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author><author><style face="normal" font="default" size="100%">Panigrahi, Priyabrata</style></author><author><style face="normal" font="default" size="100%">Brannigan, James A.</style></author><author><style face="normal" font="default" size="100%">Wilkinson, Anthony J.</style></author><author><style face="normal" font="default" size="100%">Suresh, C. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structure mediation in substrate binding and post-translational processing of penicillin acylases: Information from mutant structures of Kluyvera citrophila penicillin G acylase</style></title><secondary-title><style face="normal" font="default" size="100%">Protein Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acyl homoserine lactone</style></keyword><keyword><style  face="normal" font="default" size="100%">autocatalytic processing</style></keyword><keyword><style  face="normal" font="default" size="100%">conformational changes</style></keyword><keyword><style  face="normal" font="default" size="100%">KcPGA_Ser beta 1Cys</style></keyword><keyword><style  face="normal" font="default" size="100%">KcPGA_Ser beta 1Gly</style></keyword><keyword><style  face="normal" font="default" size="100%">Ntn hydrolase</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">OCT</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">10</style></number><publisher><style face="normal" font="default" size="100%">WILEY-BLACKWELL</style></publisher><pub-location><style face="normal" font="default" size="100%">111 RIVER ST, HOBOKEN 07030-5774, NJ USA</style></pub-location><volume><style face="normal" font="default" size="100%">24</style></volume><pages><style face="normal" font="default" size="100%">1660-1670</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Penicillin acylases are industrially important enzymes for the production of 6-APA, which is used extensively in the synthesis of secondary antibiotics. The enzyme translates into an inactive single chain precursor that subsequently gets processed by the removal of a spacer peptide connecting the chains of the mature active heterodimer. We have cloned the penicillin G acylase from Kluyvera citrophila (KcPGA) and prepared two mutants by site-directed mutagenesis. Replacement of N-terminal serine of the beta-subunit with cysteine (Ser beta 1Cys) resulted in a fully processed but inactive enzyme. The second mutant in which this serine is replaced by glycine (Ser beta 1Gly) remained in the unprocessed and inactive form. The crystals of both mutants belonged to space group P1 with four molecules in the asymmetric unit. The three-dimensional structures of these mutants were refined at resolutions 2.8 and 2.5 angstrom, respectively. Comparison of these structures with similar structures of Escherichia coli PGA (EcPGA) revealed various conformational changes that lead to autocatalytic processing and consequent removal of the spacer peptide. The large displacements of residues such as Arg168 and Arg477 toward the N-terminal cleavage site of the spacer peptide or the conformational changes of Arg145 and Phe146 near the active site in these structures suggested probable steps in the processing dynamics. A comparison between the structures of the processed Serb1Cys mutant and that of the processed form of EcPGA showed conformational differences in residues Arg alpha 145, Phe alpha 146, and Phe beta 24 at the substrate binding pocket. Three conformational transitions of Arg alpha 145 and Phe alpha 146 residues were seen when processed and unprocessed forms of KcPGA were compared with the substrate bound structure of EcPGA. Structure mediation in activity difference between KcPGA and EcPGA toward acyl homoserine lactone (AHL) is elucidated.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">3.039</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Avinash, Vellore Sunder</style></author><author><style face="normal" font="default" size="100%">Panigrahi, Priyabrata</style></author><author><style face="normal" font="default" size="100%">Chand, Deepak</style></author><author><style face="normal" font="default" size="100%">Pundle, Archana</style></author><author><style face="normal" font="default" size="100%">Suresh, Cheravakattu Gopalan</style></author><author><style face="normal" font="default" size="100%">Ramasamy, Sureshkumar</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Structural analysis of a penicillin V acylase from pectobacterium atrosepticum confirms the importance of two Trp residues for activity and specificity</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Structural Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Aromatic stacking</style></keyword><keyword><style  face="normal" font="default" size="100%">Cholylglycine hydrolase</style></keyword><keyword><style  face="normal" font="default" size="100%">molecular dynamics</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutagenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligomeric interactions</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">FEB</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">2</style></number><publisher><style face="normal" font="default" size="100%">ACADEMIC PRESS INC ELSEVIER SCIENCE</style></publisher><pub-location><style face="normal" font="default" size="100%">525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA</style></pub-location><volume><style face="normal" font="default" size="100%">193</style></volume><pages><style face="normal" font="default" size="100%">85-94</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Penicillin V acylases (PVA) catalyze the deacylation of the beta-lactam antibiotic phenoxymethylpenicillin (Pen V). They are members of the Ntn hydrolase family and possess an N-terminal cysteine as the main catalytic nucleophile residue. They form the evolutionarily related cholylglycine hydrolase (CGH) group which includes bile salt hydrolases (BSH) responsible for bile deconjugation. Even though a few PVA and BSH structures have been reported, no structure of a functional PVA from Gram-negative bacteria is available. Here, we report the crystal structure of a highly active PVA from Gram-negative Pectobacterium atrosepticum (PaPVA) at 2.5 angstrom resolution. Structural comparison with PVAs from Gram-positive bacteria revealed that PaPVA had a distinctive tetrameric structure and active site organization. In addition, mutagenesis of key active site residues and biochemical characterization of the resultant variants elucidated the role of these residues in substrate binding and catalysis. The importance of residue Trp23 and Trp87 side chains in binding and correct positioning of Pen V by PVAs was confirmed using mutagenesis and substrate docking with a 15 ns molecular dynamics simulation. These results establish the unique nature of Gram-negative CGHs and necessitate further research about their substrate spectrum. (C) 2015 Elsevier Inc. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;</style></custom3><custom4><style face="normal" font="default" size="100%">2.57</style></custom4></record></records></xml>