Identification and characterization of an equine herpesvirus 1 late gene encoding a potential zinc finger.
In this report, we present the DNA sequence and transcriptional characterization of a gene (IR5) that maps within each of the inverted repeat (IR) segments of the equine herpesvirus type 1 (EHV-1) genome. The IR5 open reading frame (ORF) is located within both IR sequences (nucleotides 9932-10,642 of the IR). DNA sequence analyses of the IR5 gene region revealed an ORF of 236 amino acids (24,793 Da) that showed significant homology to ORF64 of varicella-zoster virus and ORF3 of EHV-4 both of which map within the inverted repeats and to the US10 ORF of herpes simplex virus type 1 (HSV-1) which maps within the unique short segment. Additional analyses of the nucleotide sequence failed to reveal any overlapping ORFs that would correspond to US11 or US12 of HSV-1. Interestingly, the IR5 ORF of EHV-1 possesses a sequence of 13 amino acids (CAYWCCLGHAFAC) that is a perfect match to the consensus zinc finger motif (C-X2-4-C-X2-15-C/H-X2-4-C/H). Putative cis-acting elements flanking the IR5 ORF include a TATA box (nucleotides 9864-9870), a CAAT box (nucleotides 9709-9714), and a polyadenylation signal (nucleotides 10,645-10,650). Northern blot and S1 nuclease analyses identified a single 0.9-kb mRNA species that first appears at 2 hr postinfection, and whose synthesis is reduced in the presence of phosphonoacetic acid, an inhibitor of EHV-1 DNA synthesis. Thus, the IR5 gene of EHV-1 exhibits characteristics representative of a late gene of the gamma-1 class. The characterization of the IR5 gene at the DNA and RNA levels will facilitate ongoing studies to identify and characterize the IR5 polypeptide.
Holden
V R
VR
Department of Microbiology and Immunology, Louisiana State University Medical Center, Shreveport 71130-3932.
Yalamanchili
R R
RR
Harty
R N
RN
O'Callaghan
D J
DJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D015870:Gene Expression; D005814:Genes, Viral; D004861:Herpesvirus 1, Equid / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D016415:Sequence Alignment; D015678:Viral Structural Proteins / Q000235:genetics*; D014779:Virus Replication; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D015678:Viral Structural Proteins