Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

The Mcm2-7 complex is the eukaryotic replicative helicase.

Bochman, Matthew L. (2009) The Mcm2-7 complex is the eukaryotic replicative helicase. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

Primary Text

Download (14MB) | Preview


Replicative helicases are essential enzymes in DNA replication that separate duplex DNA into single strands to be used as templates by polymerases. The identity of these helicases in prokaryotes and viruses has been known for some time, but there is controversy in defining the eukaryotic replicative helicase. Fifteen years of in vivo work and comparison to other helicases suggests that the minichromosome maintenance proteins two through seven (Mcm2-7 complex) play this role, but in vitro DNA unwinding has never been demonstrated. In order to address this dilemma, I analyzed the biochemical activities of the Saccharomyces cerevisiae Mcm2-7 complex and the contributions of its conserved ATPase motifs to these activities. My findings indicate that Mcm2-7: 1) binds single-stranded DNA with high affinity in an ATP-dependent manner, 2) has six distinct active sites that differentially contribute to its biochemistry, and 3) is sensitive to anionic conditions in vitro. Elucidation of these characteristics led to the discovery that Mcm2-7 helicase activity is stimulated by large anions, and I was able to demonstrate bona fide in vitro DNA unwinding for the first time. The culmination of this work is the view that the Mcm2-7 complex is the true eukaryotic replicative helicase and the emerging view that Mcm2-7 ATPase active sites have evolved specialized functions within the complex.


Social Networking:
Share |


Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Bochman, Matthew L.mlb36@pitt.eduMLB36
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairSchwacha, Anthonyschwacha@pitt.eduSCHWACHA
Committee MemberBrodsky, Jeffreyjbrodsky@pitt.eduJBRODSKY
Committee MemberArndt, Karenarndt@pitt.eduARNDT
Committee MemberJen-Jacobson, Lindaljen@pitt.eduLJEN
Committee MemberTrakselis, Michaelmtraksel@pitt.eduMTRAKSEL
Committee MemberLeuba, Sanfordleuba@pitt.eduLEUBA
Date: 26 January 2009
Date Type: Completion
Defense Date: 4 September 2008
Approval Date: 26 January 2009
Submission Date: 8 September 2008
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Biological Sciences
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: ATPase; DNA replication; helicase; Mcm2-7
Other ID:, etd-09082008-155516
Date Deposited: 10 Nov 2011 20:01
Last Modified: 15 Nov 2016 13:50


Monthly Views for the past 3 years

Plum Analytics

Actions (login required)

View Item View Item