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dc.contributor.authorHjörleifsson, Jens Guðmundur
dc.contributor.authorHelland, Ronny
dc.contributor.authorMagnusdottir, Manuela
dc.contributor.authorÁsgeirsson, Bjarni
dc.date.accessioned2021-01-29T11:26:26Z
dc.date.available2021-01-29T11:26:26Z
dc.date.issued2020-11-16
dc.description.abstractThe role of surface loops in mediating communication through residue networks is still a relatively poorly understood part in the study of cold adaptation of enzymes, especially in terms of their quaternary interactions. Alkaline phosphatase (AP) from the psychrophilic marine bacterium <i>Vibrio splendidus</i> (VAP) is characterized by an analogous large surface loop in each monomer, referred to as the large loop, that hovers over the active site of the other monomer. It presumably has a role in the high catalytic efficiency of VAP which accompanies its extremely low thermal stability. Here, we designed several different variants of VAP with the aim of removing intersubunit interactions at the dimer interface. Breaking the intersubunit contacts from one residue in particular (Arg336) reduced the temperature stability of the catalytically potent conformation and caused a 40% drop in catalytic rate. The high catalytic rates of enzymes from cold‐adapted organisms are often associated with increased dynamic flexibility. Comparison of the relative B‐factors of the R336L crystal structure to that of the wild‐type confirmed surface flexibility was increased in a loop on the opposite monomer, but not in the large loop. The increase in flexibility resulted in a reduced catalytic rate. The large loop increases the area of the interface between the subunits through its contacts and may facilitate an alternating structural cycle demanded by a half‐of‐sites reaction mechanism through stronger ties, as the dimer oscillates between high affinity (active) or low phosphoryl group affinity (inactive).en_US
dc.identifier.citationHjörleifsson, Helland, Magnusdottir, Ásgeirsson. The high catalytic rate of the cold-active Vibrio alkaline phosphatase requires a hydrogen bonding network involving a large interface loop. FEBS Open Bio. 2020en_US
dc.identifier.cristinIDFRIDAID 1862938
dc.identifier.doi10.1002/2211-5463.13041
dc.identifier.issn2211-5463
dc.identifier.urihttps://hdl.handle.net/10037/20502
dc.language.isoengen_US
dc.publisherWileyen_US
dc.relation.journalFEBS Open Bio
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/SYNKNØYT/247732/Norway/Reisestøtte, synkrotron- og nøytronforskning, 2015-2017//en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2020 The Author(s)en_US
dc.subjectVDP::Mathematics and natural science: 400::Chemistry: 440en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Kjemi: 440en_US
dc.titleThe high catalytic rate of the cold-active Vibrio alkaline phosphatase requires a hydrogen bonding network involving a large interface loopen_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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