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E M McKay

Publications and source records attributed to E M McKay.

4 recordsLinked to original sources
PubMed1993

The herpes simplex virus type 1 strain 17 open reading frame RL1 encodes a polypeptide of apparent M(r) 37K equivalent to ICP34.5 of herpes simplex virus type 1 strain F.

The region between the 'a' sequence and the 5' end of the IE1 gene within the long repeat sequence of the herpes simplex virus (HSV) genome plays an important role in the neurovirulence of both HSV-1 strain F and HSV-1 strain 17. However, there has been controversy over the protein-coding potential of this region. Although an open reading frame (ORF) was predicted in HSV-1(F) and shown to encode a polypeptide called ICP34.5, only recently has a corresponding ORF, designated RL1, been recognized in HSV-1(17). To determine whether the HSV-1(17) ORF is expressed, we raised antipeptide sera against predicted amino acid sequences from RL1; one serum specifically recognized a 37K protein in HSV-1(17)-infected cell extracts. Compared with the corresponding HSV-1(F) polypeptide the HSV-1(17) protein has a lower apparent M(r), shows similar kinetics of accumulation and intracellular localization but may accumulate to lower levels than the HSV-1(F) protein. The non-neurovirulent HSV-1(17) deletion variant 1716 fails to synthesize detectable levels of ICP34.5. Thus we have established that HSV-1(17), like HSV-1(F), expresses ICP34.5, a protein important for HSV neurovirulence.

Amino Acid Sequence↗
PubMed1990

Herpes simplex virus-encoded ribonucleotide reductase: evidence for the dissociation/reassociation of the holoenzyme.

35S-labeled cells infected with herpes simplex virus type 1 (HSV-1), temperature-sensitive (ts) mutant ts 1222 were used as a source of the large subunit of the viral ribonucleotide reductase (RR) to investigate the binding of the large (RR1) and small (RR2) subunits in the active enzyme. Mixing 35S-labeled RR1 from ts 1222 with unlabeled RR1/RR2 complex from wild type (wt) infected cells resulted in the formation of a complex between 35S-labeled RR1 and unlabeled RR2, indicating that the complex between the RR1 and RR2 subunits is dynamic and subunit dissociation/reassociation occurs during enzyme function. Similar results were obtained when unlabeled HSV-2 RR was substituted for HSV-1 RR, demonstrating that the holoenzyme can be formed the large subunit of HSV-1 RR and the small subunit of HSV-2.

Amino Acid Sequence↗
PubMed1989

Reconstitution of herpes simplex virus type 1 ribonucleotide reductase activity from the large and small subunits.

An assay for the presence of functional large (RR1) and small (RR2) subunits of the herpes simplex virus type 1 (HSV-1) ribonucleotide reductase has been developed. The system utilizes two temperature-sensitive mutants, ts1207, which has a lesion in RR1, and ts1222, which has a lesion in RR2. In cells infected with ts1207 at 39.5 degrees C, the defective RR1 is unable to associate with RR2 to form an active enzyme, and, as a result, a pool of functional RR2 and defective RR1 accumulates. Evidence presented in this paper suggest that cells infected with ts1222 at either 31 degrees C or 39.5 degrees C accumulate a pool of functional RR1, but do not contain detectable RR2. Virus-specific ribonucleotide reductase activity was produced in cells coinfected with both mutants at 39.5 degrees C, each virus contributing one functional subunit to the holoenzyme. No enzyme activity was detected in cells infected with each mutant alone at this temperature. When partially purified extracts of cells infected with ts1207 at the nonpermissive temperature were mixed with those from ts1222-infected cells, a fully functional enzyme was also formed. These results demonstrate that HSV-1 ribonucleotide reductase activity can be reconstituted both in vivo and in vitro from the nondefective subunits produced by ts1222 and ts1207.

Animals↗