Show simple item record

dc.contributor.authorKopečná, Jana
dc.contributor.authorCabeza de Vaca, Israel
dc.contributor.authorAdemas, Nathan B. P.
dc.contributor.authorDavison, Paul A.
dc.contributor.authorBrindley, Amanda A.
dc.contributor.authorHunter, C. Neil
dc.contributor.authorGuallar, Víctor
dc.contributor.authorSobotka, Roman
dc.contributor.otherBarcelona Supercomputing Center
dc.date.accessioned2016-03-11T15:39:26Z
dc.date.available2016-10-07T00:30:44Z
dc.date.issued2015-10-07
dc.identifier.citationKopečná, Jana [et al.]. Porphyrin Binding to Gun4 protein, Facilitated by a Flexible Loop, Controls Metabolite Flow through the Chlorophyll Biosynthetic Pathway. "The Journal of Biological Chemistry", 07 Octubre 2015, vol. 290, p. 28477-28488.
dc.identifier.issn0021-9258
dc.identifier.urihttp://hdl.handle.net/2117/84233
dc.description.abstractIn oxygenic phototrophs, chlorophylls, hemes and bilins are synthesized by a common branched pathway. Given the phototoxic nature of tetrapyrroles, this pathway must be tightly regulated and an important regulatory role is attributed to Mgchelatase enzyme at the branching between the heme and chlorophyll pathway. Gun4 is a porphyrin-binding protein known to stimulate in vitro the Mg-chelatase activity but how the Gun4-porphyrin complex acts in the cell was unknown. To address this issue we first performed simulations to determine the porphyrin-docking mechanism to the cyanobacterial Gun4 structure. After correcting crystallographic loop contacts, we determined the binding site for Mgprotoporphyrin IX. It revealed that the orientation of 6/7 loop is critical for the binding and the magnesium ion held within the porphyrin is coordinated by Asn211 residue. We also identified the basis for stronger binding in the Gun4-1 variant and for weaker binding in the W192A mutant. The W192A-Gun4 was further characterized in Mg-chelatase assay showing that tight porphyrin-binding in Gun4 facilitates its interaction with the Mg-chelatase ChlH subunit. Finally, we introduced the W192A mutation into Synechocystis 6803 cells and show that the Gun4-porphyrin complex is important for the accumulation of ChlH and for channeling metabolites into the chlorophyll biosynthetic pathway.
dc.description.sponsorshipThis work was supported by project P501/12/G055 of the Czech Science Foundation, and by the National Programme of Sustainability I (LO1416) and by ERC 2009-Adg25027-PELE (to V.G). J.K. was supported by project Algain (EE2.3.30.0059). N.B.P.A., P.A.D., A.A.B. and C.N.H. thank the Biotechnology and Biological Sciences Research Council (BBSRC) U.K. for funding, under award numbers BB/G021546/1 and BB/M000265/1. CNH was also supported by an Advanced Award 338895 from the European Research Council.
dc.format.extent11 p.
dc.language.isoeng
dc.publisherAmerican Society for Biochemistry and Molecular Biology
dc.subjectÀrees temàtiques de la UPC::Enginyeria mecànica::Impacte ambiental
dc.subject.lcshChlorophyll--biosynthesis
dc.subject.otherChlorophyll biosynthesis
dc.subject.otherSynechocystis 6803
dc.subject.otherGun4
dc.subject.otherPorphyrins
dc.subject.otherCyanobacteria
dc.subject.otherMgprotoporphyrin IX
dc.titlePorphyrin Binding to Gun4 protein, Facilitated by a Flexible Loop, Controls Metabolite Flow through the Chlorophyll Biosynthetic Pathway
dc.typeArticle
dc.subject.lemacClorofil·la--Anàlisi
dc.identifier.doi10.1074/jbc.M115.664987
dc.description.peerreviewedPeer Reviewed
dc.relation.publisherversionhttp://www.jbc.org/content/290/47/28477.long
dc.rights.accessOpen Access
dc.description.versionPostprint (author's final draft)
dc.relation.projectidinfo:eu-repo/grantAgreement/EC/FP7/250277/EU/P.E.L.E (Protein Energy Landscape Exploration): a la carte drug design tools/PELE
local.citation.publicationNameThe Journal of Biological Chemistry
local.citation.volume290
local.citation.startingPage28477
local.citation.endingPage28488


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record