Structure and function of the prDNA and the genomic termini of the gamma2-herpesvirus bovine herpesvirus type 4.

Broll, Hermann; Buhk, Hans-Jörg; Zimmermann, Wolfgang; Goltz, Michael

doi:10.1099/0022-1317-80-4-979

Cited by 15 publications

(12 citation statements)

References 21 publications

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“…A sequence proposed as the HCMV pac2 sequence by Kemble and Mocarski has pac2 sequence characteristics but is located at an unusual position internal to pac1 within the a sequence (18). No sequences with clear pac2-like characteristics are found near the ends found on HCMV concatemers, i.e., near the other end of the a sequence from pac1 or near the terminal end of the c sequence (5,7,18,23,26). Thus, it is not possible to state that HCMV concatemer ends contain pac2 elements but only that pac1-containing ends are absent.…”

mentioning

confidence: 80%

The Ends on Herpesvirus DNA Replicative Concatemers Contain pac2 cis Cleavage/Packaging Elements and Their Formation Is Controlled by Terminal cis Sequences

McVoy

Nixon

Hur

et al. 2000

J Virol

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Herpesviruses have large double-stranded linear DNA genomes that are formed by site-specific cleavage from complex concatemeric intermediates. In this process, only one of the two genomic ends are formed on the concatemer. Although the mechanism underlying this asymmetry is not known, one explanation is that single genomes are cleaved off of concatemer ends in a preferred direction. This implies that cis elements control the direction of packaging. Two highly conserved cis elements named pac1 and pac2 lie near opposite ends of herpesvirus genomes and are important for cleavage and packaging. By comparison of published reports and by analysis of two additional herpesviruses, we found that pac2 elements lie near the ends formed on replicative concatemers of four herpesviruses: herpes simplex virus type 1, equine herpesvirus 1, guinea pig cytomegalovirus, and murine cytomegalovirus. Formation of pac2 ends on concatemers depended on terminal cis sequences, since ectopic cleavage sites engineered into the murine cytomegalovirus genome mediated formation of pac2 ends on concatemers regardless of the orientation of their insertion. These findings are consistent with a model in which pac2 elements at concatemer ends impart a directionality to concatemer packaging by binding proteins that initiate insertion of concatemer ends into empty capsids.Herpesviruses have large (130 to 235 kb) linear doublestranded DNA genomes that replicate via concatemeric intermediates consisting of head-to-tail linked genomes (1,3,17,22,23,31,32,41). The concatemers are packaged into preformed capsids and cleaved at precise locations to release unit length genomes within the capsids (31). In previous studies, we analyzed human cytomegalovirus (HCMV) concatemeric DNA for the presence of termini similar to those found on genomic DNA (23). The HCMV genome contains long and short components, or arms, that consist of unique regions flanked by inverted repeats (30). The ends of the genome are therefore referred to as the long arm end and the short arm end. We observed that HCMV concatemers contain terminal restriction fragments from the short arm end of the genome but lack terminal fragments from the long arm end (23). Similar findings of one but not both genomic termini on concatemeric DNA have since been reported for herpes simplex virus type 1 (HSV-1) (22, 32, 41) and equine herpesvirus 1 (EHV-1) (33), suggesting that this may be a characteristic of all herpesviruses. To explain our observation for HCMV, we proposed a model in which short arm termini on concatemer ends are inserted into empty capsids and packaged until full genome lengths have entered and cleavage sites are encountered. Cleavage then releases unit genomes into the capsids, generating long arm termini on the newly formed genomes and short arm termini on the newly formed concatemer ends. The short arm termini on concatemer ends are then free to encounter additional empty capsids and reinitiate the packaging process (23).The directionality proposed by this model suggests that cisac...

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mentioning

confidence: 80%

The Ends on Herpesvirus DNA Replicative Concatemers Contain pac2 cis Cleavage/Packaging Elements and Their Formation Is Controlled by Terminal cis Sequences

McVoy

Nixon

Hur

et al. 2000

J Virol

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“…The 2,267-nucleotide sequence of a single prDNA element of BoHV-4 strain 66-p-347 was published previously (6). Sequence analysis of this prDNA element showed similarities to the pac-1 and pac-2 consensus sequences of the cleavage and packaging site which is essential for the replication of the viral genome of HSV (14).…”

mentioning

confidence: 99%

“…Analysis of the predicted open reading frames (ORFs) of the prDNA indicated no homology to sequences for known proteins. It was shown that one prDNA element is sufficient for cleavage and packaging and therefore plays a key role in the replication of BoHV-4 (6).…”

mentioning

confidence: 99%

Genome Sequence of Bovine Herpesvirus 4, a Bovine Rhadinovirus, and Identification of an Origin of DNA Replication

Zimmermann

Broll

Ehlers

et al. 2001

J Virol

113

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“…In virion DNA the Uc element is adjacent to the L terminus and Ub is adjacent to the S terminus (23). Within the Ub and Uc regions are two domains, defined as pac1 and pac2, respectively, that contain several highly conserved motifs present near the ends of other herpesvirus genomes, including those lacking a terminal redundancy (5,8,9,11). The presence of these conserved sequences near the termini of herpesvirus genomes, the fact that they are brought into close proximity upon circularization, and the fact that in most instances cleavage of concatemeric DNA occurs between the pac1 and pac2 signals led to the suggestion that they have important roles in the cleavage packaging process.…”

mentioning

confidence: 99%

“…This is followed by a T-rich element (pac1 T element) and another region of high GϩC content (pac1 distal GC element). Characteristically, the pac1 T element is flanked by the sequences C n G n from the proximal GC element and G n from the distal GC element, and this unit has been proposed to represent the functional pac1 signal (5,8,11,18). Experiments with deletion mutants removing sequences from either end of the HSV-1 a sequence have shown that regions critical for cleavage and packaging reside within both Ub and Uc (11,22,27,34).…”

mentioning

confidence: 99%

Effects of Mutations within the Herpes Simplex Virus Type 1 DNA Encapsidation Signal on Packaging Efficiency

Hodge¹,

Stow²

2001

J Virol

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The cis-acting signals required for cleavage and encapsidation of the herpes simplex virus type 1 genome lie within the terminally redundant region or a sequence. The a sequence is flanked by short direct repeats (DR1) containing the site of cleavage, and quasi-unique regions, Uc and Ub, occupy positions adjacent to the genomic L and S termini, respectively, such that a novel fragment, Uc-DR1-Ub, is generated upon ligation of the genomic ends. The Uc-DR1-Ub fragment can function as a minimal packaging signal, and motifs have been identified within Uc and Ub that are conserved near the ends of other herpesvirus genomes (pac2 and pac1, respectively). We have introduced deletion and substitution mutations within the pac regions of the Uc-DR1-Ub fragment and assessed their effects on DNA packaging in an amplicon-based transient transfection assay. Within pac2, mutations affecting the T tract had the greatest inhibitory effect, but deletion of sequences on either side of this element also reduced packaging, suggesting that its position relative to other sequences within the Uc-DR1-Ub fragment is likely to be important. No single region essential for DNA packaging was detected within pac1. However, mutants lacking the G tracts on either side of the pac1 T-rich motif exhibited a reduced efficiency of serial propagation, and alteration of the sequences between DR1 and the pac1 T element also resulted in defective generation of Ub-containing terminal fragments. The data are consistent with a model in which initiation and termination of packaging are specified by sequences within Uc and Ub, respectively.Herpesviruses have linear double-stranded DNA genomes of 125 to 245 kbp that are circularized upon infection and replicate in an "endless" form, generating branched concatemeric structures. During the assembly of progeny particles, the concatemers are cleaved at specific sites corresponding to the genomic termini and, in a tightly coupled process, the viral DNA is packaged into preformed capsids (reviewed in references 13, 20, and 23).In the case of herpes simplex virus type 1 (HSV-1), the cis-acting sequences required for cleavage and packaging reside within the terminally redundant region or a sequence (21,29,32,34). The a sequence is 250 to 500 bp long and present as a single copy at the S terminus and one or more tandem copies at the L terminus. In addition, one or more copies are also present in inverted orientation at the junction between the L and S segments (23).Flanking the a sequences are direct repeats (DR1) of 17 to 20 bp, with single copies of DR1 separating tandem a sequences. The site of genomic cleavage occurs within the DR1 element such that a single copy is regenerated upon ligation of the two genomic ends (see Fig. 1). The central portion of the a sequence comprises multiple tandem reiterations of one or two other short sequence elements (11 to 24 bp) referred to as DR2 and DR4. The quasi-unique sequences, each of ca. 80 bp, which lie between DR1 and either side of the DR2 and DR4 repeats are termed the ...

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Structure and function of the prDNA and the genomic termini of the gamma2-herpesvirus bovine herpesvirus type 4.

Cited by 15 publications

References 21 publications

The Ends on Herpesvirus DNA Replicative Concatemers Contain pac2 cis Cleavage/Packaging Elements and Their Formation Is Controlled by Terminal cis Sequences

The Ends on Herpesvirus DNA Replicative Concatemers Contain pac2 cis Cleavage/Packaging Elements and Their Formation Is Controlled by Terminal cis Sequences

Genome Sequence of Bovine Herpesvirus 4, a Bovine Rhadinovirus, and Identification of an Origin of DNA Replication

Effects of Mutations within the Herpes Simplex Virus Type 1 DNA Encapsidation Signal on Packaging Efficiency

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