1LTL

THE DODECAMER STRUCTURE OF MCM FROM ARCHAEAL M. THERMOAUTOTROPHICUM

Summary for 1LTL

• Entry DOI: 10.2210/pdb1ltl/pdb
• Descriptor: DNA replication initiator (Cdc21/Cdc54), ZINC ION (2 entities in total)
• Functional Keywords: replication
• Biological source: Methanothermobacter thermautotrophicus
• Total number of polymer chains: 6
• Total formula weight: 194412.43

Authors

Fletcher, R.J.,Bishop, B.E.,Leon, R.P.,Sclafani, R.A.,Ogata, C.M.,Chen, X.S. (deposition date: 2002-05-20, release date: 2003-05-27, Last modification date: 2024-02-14)

Primary citation

Fletcher, R.J.,Bishop, B.E.,Leon, R.P.,Sclafani, R.A.,Ogata, C.M.,Chen, X.S.
The Structure and function of MCM from archaeal M. Thermoautotrophicum
Nat.Struct.Biol., 10:160-167, 2003

PubMed Abstract: Eukaryotic chromosomal DNA is licensed for replication precisely once in each cell cycle. The mini-chromosome maintenance (MCM) complex plays a role in this replication licensing. We have determined the structure of a fragment of MCM from Methanobacterium thermoautotrophicum (mtMCM), a model system for eukaryotic MCM. The structure reveals a novel dodecameric architecture with a remarkably long central channel. The channel surface has an unusually high positive charge and binds DNA. We also show that the structure of the N-terminal fragment is conserved for all MCMs proteins despite highly divergent sequences, suggesting a common architecture for a similar task: gripping/remodeling DNA and regulating MCM activity. An mtMCM mutant protein equivalent to a yeast MCM5 (CDC46) protein with the bob1 mutation at its N terminus has only subtle structural changes, suggesting a Cdc7-bypass mechanism by Bob1 in yeast. Yeast bypass experiments using MCM5 mutant proteins support the hypothesis for the bypass mechanism.

PubMed: 12548282
DOI: 10.1038/nsb893

Experimental method

X-RAY DIFFRACTION (3 Å)