scholarly journals Structural basis of DNA replication origin recognition by human Orc6 protein binding with DNA

2020 ◽  
Vol 48 (19) ◽  
pp. 11146-11161
Author(s):  
Naining Xu ◽  
Yingying You ◽  
Changdong Liu ◽  
Maxim Balasov ◽  
Lee Tung Lun ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Binding ◽  
Solution Structure ◽  
Origin Recognition Complex ◽  
Structural Basis ◽  
Dna Replication Origin ◽  
Dna Alterations ◽  
Replication Initiator ◽  
Binding Subunit ◽  
Origin Recognition

Abstract The six-subunit origin recognition complex (ORC), a DNA replication initiator, defines the localization of the origins of replication in eukaryotes. The Orc6 subunit is the smallest and the least conserved among ORC subunits. It is required for DNA replication and essential for viability in all species. Orc6 in metazoans carries a structural homology with transcription factor TFIIB and can bind DNA on its own. Here, we report a solution structure of the full-length human Orc6 (HsOrc6) alone and in a complex with DNA. We further showed that human Orc6 is composed of three independent domains: N-terminal, middle and C-terminal (HsOrc6-N, HsOrc6-M and HsOrc6-C). We also identified a distinct DNA-binding domain of human Orc6, named as HsOrc6-DBD. The detailed analysis of the structure revealed novel amino acid clusters important for the interaction with DNA. Alterations of these amino acids abolish DNA-binding ability of Orc6 and result in reduced levels of DNA replication. We propose that Orc6 is a DNA-binding subunit of human/metazoan ORC and may play roles in targeting, positioning and assembling the functional ORC at the origins.

scholarly journals The architecture of the DNA replication origin recognition complex in Saccharomyces cerevisiae

2008 ◽  
Vol 105 (30) ◽  
pp. 10326-10331 ◽  
Author(s):  
Z. Chen ◽  
C. Speck ◽  
P. Wendel ◽  
C. Tang ◽  
B. Stillman ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Replication ◽  
Replication Origin ◽  
Origin Recognition Complex ◽  
Dna Replication Origin ◽  
Origin Recognition

scholarly journals Architecture of the yeast origin recognition complex bound to origins of DNA replication.

1997 ◽  
Vol 17 (12) ◽  
pp. 7159-7168 ◽  
Author(s):  
D G Lee ◽  
S P Bell
Keyword(s):  
Dna Replication ◽  
Dna Binding ◽  
Origin Recognition Complex ◽  
Binding Assays ◽  
Chromosomal Replication ◽  
Origins Of Replication ◽  
Eukaryotic Dna ◽  
Level Of Analysis ◽  
Origin Recognition

In many organisms, the replication of DNA requires the binding of a protein called the initiator to DNA sites referred to as origins of replication. Analyses of multiple initiator proteins bound to their cognate origins have provided important insights into the mechanism by which DNA replication is initiated. To extend this level of analysis to the study of eukaryotic chromosomal replication, we have investigated the architecture of the Saccharomyces cerevisiae origin recognition complex (ORC) bound to yeast origins of replication. Determination of DNA residues important for ORC-origin association indicated that ORC interacts preferentially with one strand of the ARS1 origin of replication. DNA binding assays using ORC complexes lacking one of the six subunits demonstrated that the DNA binding domain of ORC requires the coordinate action of five of the six ORC subunits. Protein-DNA cross-linking studies suggested that recognition of origin sequences is mediated primarily by two different groups of ORC subunits that make sequence-specific contacts with two distinct regions of the DNA. Implications of these findings for ORC function and the mechanism of initiation of eukaryotic DNA replication are discussed.

Structural Basis of DNA Replication Origin Recognition by an ORC Protein

Science ◽  
2007 ◽  
Vol 317 (5842) ◽  
pp. 1213-1216 ◽  
Author(s):  
M. Gaudier ◽  
B. S. Schuwirth ◽  
S. L. Westcott ◽  
D. B. Wigley
Keyword(s):  
Dna Replication ◽  
Replication Origin ◽  
Structural Basis ◽  
Dna Replication Origin ◽  
Origin Recognition

scholarly journals Identification of a Preinitiation Step in DNA Replication That Is Independent of Origin Recognition Complex and cdc6, but Dependent on cdk2

1998 ◽  
Vol 140 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Xuequn Helen Hua ◽  
John Newport
Keyword(s):  
Dna Replication ◽  
Origin Recognition Complex ◽  
Minichromosome Maintenance ◽  
Cdk2 Activity ◽  
Proteolytic Pathway ◽  
Egg Extracts ◽  
Dna Replication Origin ◽  
Initiation Of Dna Replication ◽  
Mcm Proteins ◽  
Origin Recognition

Before initiation of DNA replication, origin recognition complex (ORC) proteins, cdc6, and minichromosome maintenance (MCM) proteins bind to chromatin sequentially and form preinitiation complexes. Using Xenopus laevis egg extracts, we find that after the formation of these complexes and before initiation of DNA replication, cdc6 is rapidly removed from chromatin, possibly degraded by a cdk2-activated, ubiquitin-dependent proteolytic pathway. If this displacement is inhibited, DNA replication fails to initiate. We also find that after assembly of MCM proteins into preinitiation complexes, removal of the ORC from DNA does not block the subsequent initiation of replication. Importantly, under conditions in which both ORC and cdc6 protein are absent from preinitiation complexes, DNA replication is still dependent on cdk2 activity. Therefore, the final steps in the process leading to initiation of DNA replication during S phase of the cell cycle are independent of ORC and cdc6 proteins, but dependent on cdk2 activity.

Structure of the origin recognition complex bound to DNA replication origin

Nature ◽  
2018 ◽  
Vol 559 (7713) ◽  
pp. 217-222 ◽  
Author(s):  
Ningning Li ◽  
Wai Hei Lam ◽  
Yuanliang Zhai ◽  
Jiaxuan Cheng ◽  
Erchao Cheng ◽  
...  
Keyword(s):  
Dna Replication ◽  
Replication Origin ◽  
Origin Recognition Complex ◽  
Dna Replication Origin ◽  
Origin Recognition

Identification and characterization of the DNA replication origin recognition complex gene family in the silkworm Bombyx mori

2011 ◽  
Vol 31 (5) ◽  
pp. 353-361 ◽  
Author(s):  
Hui-Peng Yang ◽  
Su-Juan Luo ◽  
Yi-Nü Li ◽  
Yao-Zhou Zhang ◽  
Zhi-Fang Zhang
Keyword(s):  
Dna Replication ◽  
Bombyx Mori ◽  
Replication Origin ◽  
Origin Recognition Complex ◽  
Bioinformatic Analysis ◽  
Replication Complex ◽  
Dna Replication Origin ◽  
Rapid Amplification ◽  
Replication Factors ◽  
Origin Recognition

The ORC (origin recognition complex) binds to the DNA replication origin and recruits other replication factors to form the pre-replication complex. The cDNA and genomic sequences of all six subunits of ORC in Bombyx mori (BmORC1–6) were determined by RACE (rapid amplification of cDNA ends) and bioinformatic analysis. The conserved domains were identified in BmOrc1p–6p and the C-terminal of BmOrc6p features a short sequence that may be specific for Lepidoptera. As in other organisms, each of the six BmORC subunits had evolved individually from ancestral genes in early eukaryotes. During embryo development, the six genes were co-regulated, but different ratios of the abundance of mRNAs were observed in 13 tissues of the fifth instar day-6 larvae. Infection by BmNPV (B. mori nucleopolyhedrovirus) initially decreased and then increased the abundance of BmORC. We suggest that some of the BmOrc proteins may have additional functions and that BmOrc proteins participate in the replication of BmNPV.

scholarly journals Role of the Orc6 Protein in Origin Recognition Complex-Dependent DNA Binding and Replication in Drosophila melanogaster

2007 ◽  
Vol 27 (8) ◽  
pp. 3143-3153 ◽  
Author(s):  
Maxim Balasov ◽  
Richard P. H. Huijbregts ◽  
Igor Chesnokov
Keyword(s):  
Amino Acids ◽  
Dna Replication ◽  
Dna Binding ◽  
Origin Recognition Complex ◽  
Dominant Negative ◽  
The Core ◽  
Culture Cells ◽  
Replication Domain ◽  
Origin Recognition

ABSTRACT The six-subunit origin recognition complex (ORC) is a DNA replication initiator protein in eukaryotes that defines the localization of the origins of replication. We report here that the smallest Drosophila ORC subunit, Orc6, is a DNA binding protein that is necessary for the DNA binding and DNA replication functions of ORC. Orc6 binds DNA fragments containing Drosophila origins of DNA replication and prefers poly(dA) sequences. We have defined the core replication domain of the Orc6 protein which does not include the C-terminal domain. Further analysis of the core replication domain identified amino acids that are important for DNA binding by Orc6. Alterations of these amino acids render reconstituted Drosophila ORC inactive in DNA binding and DNA replication. We show that mutant Orc6 proteins do not associate with chromosomes in vivo and have dominant negative effects in Drosophila tissue culture cells. Our studies provide a molecular analysis for the functional requirement of Orc6 in replicative functions of ORC in Drosophila and suggest that Orc6 may contribute to the sequence preferences of ORC in targeting to the origins.

scholarly journals Systemic Analysis of the Dna Replication Regulators Origin Recognition Complex in Lung Adenocarcinomas Identifies Prognostic and Expression Significance

2021 ◽  
Author(s):  
Yun-bo Deng ◽  
Juan Chen ◽  
Xian-yu Luo ◽  
Tian Zeng ◽  
Dong-mei Ye ◽  
...  
Keyword(s):  
Protein Structure ◽  
Dna Replication ◽  
Origin Recognition Complex ◽  
Functional Enrichment ◽  
Ppi Network ◽  
Immune Infiltration ◽  
Systemic Analysis ◽  
Lung Adenocarcinomas ◽  
Replication Initiator ◽  
Origin Recognition

Abstract Background: Origin recognition complex (ORC) 1, ORC2, ORC3, ORC4, ORC5 and ORC6, form a replication-initiator complex to mediate DNA replication, which play a key role in carcinogenesis, while their role in lung adenocarcinomas (LUAD) remains poorly understood.Methods: We confirmed the transcriptional and post-transcriptional levels, DNA alteration, DNA methylation, miRNA network, protein structure, PPI network, functional enrichment, immune infiltration and prognostic value of ORCs in LUAD based on Oncomine, GEPIA, HPA, cBioportal, TCGA, GeneMANIA, Metascape, KM-plot, GENT2, and TIMER database. Results: ORC mRNA and protein were both enhanced obviously based on Oncomine, Ualcan, GEPIA, TCGA and HPA database. Furthermore, ORC1 and ORC6 have significant prognostic values for LUAD patients based on GEPIA database. Protein structure, PPI network, functional enrichment and immune infiltration analysis indicated that ORC complex cooperatively accelerate the LUAD development by promoting DNA replication, cellular senescence and metabolic process. Conclusion: the ORC complex has an important prognostic and expression significance for LUAD patients.

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