CHARACTERIZATION OF THE GENOME OF MOLLUSCUM CONTAGIOSUM VIRUS TYPE-1 BETWEEN THE GENOME COORDINATES 0.045 AND 0.075 BY DNA NUCLEOTIDE-SEQUENCE ANALYSIS OF A 5.6-KB HINDIII MLUI DNA FRAGMENT/

The complete DNA nucleotide sequence of a HindIII/MluI genomic DNA fra gment (0.045-0.075 viral map units) from molluscum contagiosum virus t ype 1 (MCV-1) was determined. The HindIII/MluI DNA fragment comprises 5,646 bp with a base composition of 64.4% G + C and 35.6% A + T. The D NA sequence contains many perfect direct repeats. A cluster of three r epetitive DNA elements R1, R2 and R3, with a complex structural arrang ement was detected between nucleotide positions 1802 and 2107. The uni t length (box) of the repetitive DNA sequences was found to be 6 bp (1 5 boxes) and 9 bp (24 boxes) for R1 and R2, respectively. The repetiti ve DNA element R3 is organized in fifteen boxes (15 bp) in which a uni t length of R1 is combined with a unit length of R2. The arrangement o f the repetition R3 within the DNA sequences of this particular region of the MCV-1 genome was found to be (5 x R3) + (2 x R2) + (1 x R3) (6 x R2) + (1 x R3) + (1 x R2) + (8 x R3). Twenty-three open reading f rames (ORFs) of 60-1,175 amino acid (AA) residues were detected. The l argest ORF (number 17) comprises 1,175 AA with a predicted molecular w eight of 126 kD. This ORF harbors a promoter signal which is located 2 1 nucleotides upstream from the start codon and is very similar to the early promoter signals known for vaccinia virus. This putative protei n contains glutamine-enriched regions between AA residues 427 and 682 which show homologies to the corresponding glutamine-enriched regions of a variety of cellular genes like human transcriptional initiation f actor (TFIID: TATA box factor).