Matches in SemOpenAlex for { <https://semopenalex.org/work/W834666058> ?p ?o ?g. }
Showing items 1 to 65 of
65
with 100 items per page.
- W834666058 abstract "The insertion of Mg2+ into protoporphyrin IX represents the first committed step in the chlorophyll and bacteriochlorophyll biosynthetic pathways. The reaction is catalyzed by the multisubunit enzyme Mg-chelatase, which consists of three subunits, known as I (molecular weight ~40 kDa), D (~70 kDa), and H (~140 kDa). To fully understand this first step in chlorophyll biosynthesis each protein component of Mg-chelatase needs to be characterized and be coupled into a context of its macromolecular ensemble. Thus it is vital to study the 3D structure of individual modules, but to gain full functional insight into the system the structure and dynamics of the catalytic assemblies needs to be determined.The results presented in this thesis are mainly derived from electron microscopy (EM) single-particle techniques. In combination with several other established methods in protein characterization, e.g. X-ray crystallography, bioinformatics, biochemical assays and mass-spectrometry it has provided a poweful tool to obtain quasi-atomic information of the structure and dynamics of R. capsulatus Mg-chelatase. It is presented here that the I- and D-subunits form bipartite chaperone-like complex (ID-complex) with a C3 point-group symmetry and the single-particle cryo-EM 3D reconstruction of the ID-complex in presence of ADP is solved to 7.5 A resolution.The largest subunit H, carries the protoporphyrin IX, and it is known to associate with a preformed ID-complex. The results presented here give the first insights into the structure of an H-subunit. Single-particle EM 3D-reconstruction was used to solve the structure in apo and substrate bound conformations at resolution of 25 A, and revealed a conformational change upon substrate binding. Limited proteolysis and construction of truncated H polypeptides provided supporting information to propose a cooperative substrate binding model.The presented quasi-atomic model of the ADP-induced ID-complex reveals the complex structure of the D-ring, which belongs to a unique clade of ATPase inactive AAA+ proteins that has not yet been characterized structurally, and how it assembles with the ATPase active I-ring. Furthermore, the ID-complex is an ATP-fuelled AAA+ motor that is most likely dependent upon ATP-hydrolysis for the conformational rearrangement that is required before H-subunit association may take place and the metal insertion can be completed. An autoinhibitory mechanism for the ATP-fuelled motions of the ID-complex is presented, that may be of general importance for the mechanistic understanding of all bipartite AAA+ family members." @default.
- W834666058 created "2016-06-24" @default.
- W834666058 creator A5035155322 @default.
- W834666058 date "2007-01-01" @default.
- W834666058 modified "2023-09-26" @default.
- W834666058 title "Insights into structure and dynamics of the AAA+ motor of magnesium chelatase" @default.
- W834666058 hasPublicationYear "2007" @default.
- W834666058 type Work @default.
- W834666058 sameAs 834666058 @default.
- W834666058 citedByCount "0" @default.
- W834666058 crossrefType "dissertation" @default.
- W834666058 hasAuthorship W834666058A5035155322 @default.
- W834666058 hasConcept C104292427 @default.
- W834666058 hasConcept C104317684 @default.
- W834666058 hasConcept C139425391 @default.
- W834666058 hasConcept C143065580 @default.
- W834666058 hasConcept C151730666 @default.
- W834666058 hasConcept C185592680 @default.
- W834666058 hasConcept C20702342 @default.
- W834666058 hasConcept C2777850835 @default.
- W834666058 hasConcept C2779343474 @default.
- W834666058 hasConcept C54355233 @default.
- W834666058 hasConcept C55493867 @default.
- W834666058 hasConcept C8010536 @default.
- W834666058 hasConcept C86803240 @default.
- W834666058 hasConceptScore W834666058C104292427 @default.
- W834666058 hasConceptScore W834666058C104317684 @default.
- W834666058 hasConceptScore W834666058C139425391 @default.
- W834666058 hasConceptScore W834666058C143065580 @default.
- W834666058 hasConceptScore W834666058C151730666 @default.
- W834666058 hasConceptScore W834666058C185592680 @default.
- W834666058 hasConceptScore W834666058C20702342 @default.
- W834666058 hasConceptScore W834666058C2777850835 @default.
- W834666058 hasConceptScore W834666058C2779343474 @default.
- W834666058 hasConceptScore W834666058C54355233 @default.
- W834666058 hasConceptScore W834666058C55493867 @default.
- W834666058 hasConceptScore W834666058C8010536 @default.
- W834666058 hasConceptScore W834666058C86803240 @default.
- W834666058 hasLocation W8346660581 @default.
- W834666058 hasOpenAccess W834666058 @default.
- W834666058 hasPrimaryLocation W8346660581 @default.
- W834666058 hasRelatedWork W168378882 @default.
- W834666058 hasRelatedWork W1977900635 @default.
- W834666058 hasRelatedWork W1984969485 @default.
- W834666058 hasRelatedWork W1990139313 @default.
- W834666058 hasRelatedWork W1992334712 @default.
- W834666058 hasRelatedWork W2006732618 @default.
- W834666058 hasRelatedWork W2021105852 @default.
- W834666058 hasRelatedWork W2022049371 @default.
- W834666058 hasRelatedWork W2055982130 @default.
- W834666058 hasRelatedWork W2064618359 @default.
- W834666058 hasRelatedWork W2067143036 @default.
- W834666058 hasRelatedWork W2073904681 @default.
- W834666058 hasRelatedWork W2087963569 @default.
- W834666058 hasRelatedWork W2096616374 @default.
- W834666058 hasRelatedWork W2103432825 @default.
- W834666058 hasRelatedWork W2195872026 @default.
- W834666058 hasRelatedWork W2264392503 @default.
- W834666058 hasRelatedWork W2293125109 @default.
- W834666058 hasRelatedWork W2995788702 @default.
- W834666058 hasRelatedWork W3190547115 @default.
- W834666058 isParatext "false" @default.
- W834666058 isRetracted "false" @default.
- W834666058 magId "834666058" @default.
- W834666058 workType "dissertation" @default.