pH-Controlled Quaternary States of Hexameric DnaB Helicase
dc.contributor.author | Donate, Luis Enrique | |
dc.contributor.author | Llorca, O | |
dc.contributor.author | Barcena, M | |
dc.contributor.author | Brown, Susan Elizabeth | |
dc.contributor.author | Dixon, Nicholas | |
dc.contributor.author | Carazo, Jose-Maria | |
dc.date.accessioned | 2015-12-13T23:18:32Z | |
dc.date.issued | 2000 | |
dc.date.updated | 2015-12-12T08:57:14Z | |
dc.description.abstract | DnaB is the major helicase in the Escherichia coli replisome. It is a homohexameric enzyme that interacts with many other replisomal proteins and cofactors. It is usually loaded onto a single strand of DNA at origins of replication from its complex with its loading partner DnaC, then translocates in the 5' to 3' direction, unwinding duplex DNA in an NTP-driven process. Quaternary polymorphism has been described for the DnaB oligomer, a feature it has in common with some other hexameric helicases. In the present work, electron microscopy and indepth rotational analysis studies of negatively stained specimens has allowed the establishment of conditions that govern the transition between the two different rotational symmetry states (C3 and C6) of DnaB. It is shown: (a) that the pH value of the sample buffer, within the physiological range, dictates the quaternary organisation of the DnaB oligomer; (b) that the pH-induced transition is fully reversible; (c) that the type of adenine nucleotide complexed to DnaB, whether hydrolysable or not, does not affect its quaternary architecture; (d) that the DnaB ยท DnaC complex exists only as particles with C3 symmetry; and (e) that DnaC interacts only with DnaB particles that have C3 symmetry. Structural consequences of this quaternary polymorphism, as well as its functional implications for helicase activity, are discussed. (C) 2000 Academic Press. | |
dc.identifier.issn | 0022-2836 | |
dc.identifier.uri | http://hdl.handle.net/1885/90221 | |
dc.publisher | Elsevier | |
dc.source | Journal of Molecular Biology | |
dc.subject | Keywords: DNA B; helicase; article; DNA binding; DNA polymorphism; DNA replication; DNA structure; enzyme activity; Escherichia coli; pH; priority journal; Adenosine Diphosphate; Adenosine Triphosphate; Adenylyl Imidodiphosphate; Bacterial Proteins; DNA Helicases; DNA replication; DnaB; Electron microscopy; Hexameric helicases and quaternary polymorphism; Image analysis | |
dc.title | pH-Controlled Quaternary States of Hexameric DnaB Helicase | |
dc.type | Journal article | |
local.bibliographicCitation.issue | 3 | |
local.bibliographicCitation.lastpage | 393 | |
local.bibliographicCitation.startpage | 383 | |
local.contributor.affiliation | Donate, Luis Enrique, Universidad Autonoma de Madrid | |
local.contributor.affiliation | Llorca, O, Centro Nacional de Biotecnologรญa (CSIC) | |
local.contributor.affiliation | Barcena, M, Universidad Autonoma de Madrid | |
local.contributor.affiliation | Brown, Susan Elizabeth, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Dixon, Nicholas, College of Physical and Mathematical Sciences, ANU | |
local.contributor.affiliation | Carazo, Jose-Maria, Universidad Autonoma de Madrid | |
local.contributor.authoremail | repository.admin@anu.edu.au | |
local.contributor.authoruid | Brown, Susan Elizabeth, u970196 | |
local.contributor.authoruid | Dixon, Nicholas, u8102891 | |
local.description.embargo | 2037-12-31 | |
local.description.notes | Imported from ARIES | |
local.description.refereed | Yes | |
local.identifier.absfor | 030503 - Organic Chemical Synthesis | |
local.identifier.ariespublication | MigratedxPub20523 | |
local.identifier.citationvolume | 303 | |
local.identifier.doi | 10.1006/jmbi.2000.4132 | |
local.identifier.scopusID | 2-s2.0-0034721948 | |
local.identifier.uidSubmittedBy | Migrated | |
local.type.status | Published Version |
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