The herpes simplex virus type 1 origin-binding protein interacts specifically with the viral UL8 protein

McLean, Gordon W.; Abbotts, Adrian P.; Parry, Marc E.; Marsden, Howard S.; Stow, Nigel D.

doi:10.1099/0022-1317-75-10-2699

Cited by 79 publications

(76 citation statements)

References 25 publications

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“…UL9 protein interacts with ICP8 (23), UL8 protein, a component of the trimeric helicase͞primase (46), and UL42 protein, the DNA polymerase accessory protein (47). The G͞C-rich flanking sequences contain multiple binding sites for transcriptional factors, and their presence has been shown to stimulate replication significantly (41,45).…”

Section: Discussionmentioning

confidence: 99%

Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: Visualization of a specific preunwinding complex

Makhov

Lee

Lehman

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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Herpes simplex virus 1 contains three origins of replication; two copies of oriS and one of a similar sequence, oriL. Here, the combined action of multiple factors known or thought to influence the opening of oriS are examined. These include the viral originbinding protein, UL9, and single-strand binding protein ICP8, host cell topoisomerase I, and superhelicity of the DNA template. By using electron microscopy, it was observed that when ICP8 and UL9 proteins were added together to oriS-containing supertwisted DNA, a discrete preunwinding complex was formed at oriS on 40% of the molecules, which was shown by double immunolabeling electron microscopy to contain both proteins. This complex was relatively stable to extreme dilution. Addition of ATP led to the efficient unwinding of Ϸ50% of the DNA templates. Unwinding proceeded until the acquisition of a high level of positive supertwists in the remaining duplex DNA inhibited further unwinding. Addition of topoisomerase I allowed further unwinding, opening >1 kb of DNA around oriS.T he initiation of DNA replication for most genomes begins with the recognition of the origin by specific origin-binding proteins. Binding frequently is accompanied by a structural alteration in the DNA that promotes unwinding and entry of the proteins required to initiate DNA synthesis (1, 2). Some origin-binding proteins also exhibit helicase activity, which facilitates origin unwinding, and several form hexamers or double hexamers on the DNA, a structure typical of many helicases; examples include simian virus 40 T antigen (3-5) and the E1 protein of the papillomaviruses (6, 7). Herpes simplex virus 1 (HSV-1) UL9 protein provides origin recognition function but binds as a double dimer to the HSV-1 origins rather than as a hexamer (8-10).HSV-1 provides an excellent system for study of these early replication steps in a mammalian system. The HSV-1 genome encodes seven proteins required for origin-dependent DNA replication consisting of a DNA polymerase and its accessory protein, a heterotrimeric helicase-primase, a single-stranded (ss) DNAbinding protein, ICP8, and the origin-binding protein, UL9 protein (11-16). HSV-1 contains three functional origins of DNA replication. One, oriL, is present in the long unique segment of the genome, whereas the other highly homologous origin, oriS, is present twice in the repeat region flanking the short unique segment (17)(18)(19)(20). The minimal functional oriS sequence (79 bp) consists of a 45-bp inverted repeat containing a central A͞T-rich element flanked on each side by two high-affinity UL9 proteinbinding sites designated box I and box II. A third weaker UL9 protein-binding site, box III, is located adjacent to box I.ICP8 is the major ssDNA-binding protein coded by the HSV-1 genome. ICP8 stimulates the helicase activity of UL9 protein (21, 22) and binds to its C-terminal domain (23). The ICP8-UL9 protein interaction is stable in the presence of double-stranded DNA but not ssDNA likely due to the strong affinity of ICP8 for ssDNA (9,24).UL9 prot...

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Section: Discussionmentioning

confidence: 99%

Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: Visualization of a specific preunwinding complex

Makhov

Lee

Lehman

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

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“…A further specific interaction of origin-bound UL9 with the UL8 component of the viral helicase-primase complex is possibly also important for initial unwinding of the origin region. Interestingly, the interaction with UL8 involves sequences which lie within the functional helicase domain we have identified (McLean et al, 1994), whilst sequences at the C terminus of UL9 that are dispensable for origin binding contribute to the interaction with, and stimulation of helicase activity by, ICP8 (Boehmer et al, 1994). Finally, our data are consistent with the sequencespecific origin-binding and DNA helicase activities of UL9 being independent functions carried out by distinct domains of the protein.…”

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confidence: 99%

“…The recombinant baculoviruses AcUL9 and AcUL9NT express full-length UL9 and amino acids 1-535 respectively (Stow, 1992;McLean et al, 1994). A recombinant, AcRP231acZ (Possee & Howard, 1987), which expresses fl-galactosidase was employed as a control.…”

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confidence: 99%

The origin-binding domain of the herpes simplex virus type 1 UL9 protein is not required for DNA helicase activity

Abbotts¹,

Stow²

1995

Journal of General Virology

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The UL9 protein of herpes simplex virus type 1 binds to specific sequences within the viral origins of DNA replication and also functions as a DNA helicase. The C-terminal 317 amino acids of the 851 residue protein specify sequence-specific binding to the viral origins and the N-terminal 400 contain several motifs characteristic of many DNA and RNA helicases. To investigate whether the origin-binding domain is required for helicase function we have expressed a truncated version comprising amino acids 1-535 of UL9 using a recombinant baculovirus. Extracts were prepared from cells infected with the recombinant virus and chromatographer over ATP-agarose. DNA helicase, DNAdependent ATPase and a novel single-stranded DNAbinding activity were present in fractions containing the truncated UL9 protein but not in corresponding gradient fractions from a control virus infection. These results indicate that the DNA helicase function of UL9 does not require the presence of the origin-binding domain and suggest that an interaction between the N-terminal domain and distorted or partially single-stranded regions of DNA may play a role in unwinding the origin region.

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“…In the first instance, ICP8 is recruited to participate in the aforementioned distortion and unwinding steps (66). Subsequently, UL9, through its interaction with the UL8 loading protein (67), may recruit the viral helicase-primase to initiate primer synthesis and to establish a bi-directional replication fork. The viral DNA polymerase may be recruited to the site of initiation either by the interaction of its catalytic subunit (UL30) with UL8 (68) or via an interaction between its processivity factor (UL42) and UL9 (69).…”

Section: Initiation Of Replicationmentioning

confidence: 99%

Herpes Virus Replication

Boehmer

Nimonkar

2003

IUBMB Life

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SummaryHerpesviruses are large double stranded DNA animal viruses with the distinguishing ability to establish latent, life-long infections. To date, eight human herpesviruses that exhibit distinct biological and corresponding pathological/clinical properties have been identified. During their life cycles, herpesviruses execute an intricate chain of events geared towards optimizing their replication. This sets an interesting paradigm to study fundamental biological processes. This review summarizes recent developments in herpesvirus research with emphasis on genome transactions, particularly with respect to the prototypic herpes simplex virus type-1. IUBMB Life, 55: 13-22, 2003

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The herpes simplex virus type 1 origin-binding protein interacts specifically with the viral UL8 protein

Cited by 79 publications

References 25 publications

Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: Visualization of a specific preunwinding complex

Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: Visualization of a specific preunwinding complex

The origin-binding domain of the herpes simplex virus type 1 UL9 protein is not required for DNA helicase activity

Herpes Virus Replication

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