3M03

Crystal structure of human Orc6 fragment

Summary for 3M03

• Entry DOI: 10.2210/pdb3m03/pdb
• Descriptor: Origin recognition complex subunit 6, 2-(N-MORPHOLINO)-ETHANESULFONIC ACID, SULFATE ION, ... (4 entities in total)
• Functional Keywords: helix turn helix, dna binding protein, origin recognition complex, dna replication
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: Q9Y5N6
• Total number of polymer chains: 3
• Total formula weight: 31753.42

Authors

Liu, S.X.,Wu, L.J.,Sun, J.,Wang, H.F.,Liu, Y.F. (deposition date: 2010-03-02, release date: 2011-03-09, Last modification date: 2024-10-16)

Primary citation

Liu, S.X.,Balasov, M.,Wang, H.F.,Wu, L.J.,Chesnokov, I.N.,Liu, Y.F.
Structural analysis of human Orc6 protein reveals a homology with transcription factor TFIIB
Proc.Natl.Acad.Sci.USA, 108:7373-7378, 2011

PubMed Abstract: The Origin Recognition Complex (ORC) is a six-subunit protein important for the initiation of DNA replication in eukaryotic cells. Orc6 is the smallest and the least conserved among ORC subunits. It is required for the DNA replication but also has a function in cytokinesis in metazoan species, however, the mechanisms of Orc6 action in these processes are not clear. Here we report a structure of the middle domain of human Orc6. This domain has an overall fold similar to the corresponding helical domain of transcription factor TFIIB. Based on these findings, a model of Orc6 binding to DNA is produced. We have identified amino acids of Orc6 which are directly involved in DNA binding. Alterations of these amino acids abolish DNA binding ability of Orc6 and also result in reduced levels of DNA replication in vitro and in cultured cells. Our data indicate that Orc6 is one of the DNA binding subunits of ORC in metazoan species. We propose that Orc6 may participate in positioning of ORC at the origins of DNA replication similar to the role of TFIIB in positioning transcription preinitiation complex at the promoter.

PubMed: 21502537
DOI: 10.1073/pnas.1013676108

Experimental method

X-RAY DIFFRACTION (2.5 Å)