title: The conserved baculovirus protein p33 (Ac92) is a flavin adenine dinucleotide-linked sulfhydryl oxidase.
abstract: Open reading frame 92 of the Autographa californica baculovirus (Ac92) is one of about 30 core genes present in all sequenced baculovirus genomes. Computer analyses predicted that the Ac92 encoded protein (called p33) and several of its baculovirus orthologs were related to a family of flavin adenine dinucleotide (FAD)-linked sulfhydryl oxidases. Alignment of these proteins indicated that, although they were highly diverse, a number of amino acids in common with the Erv1p/Alrp family of sulfhydryl oxidases are present. Some of these conserved amino acids are predicted to stack against the isoalloxazine and adenine components of FAD, whereas others are involved in electron transfer. To investigate this relationship, Ac92 was expressed in bacteria as a His-tagged fusion protein, purified, and characterized both spectrophotometrically and for its enzymatic activity. The purified protein was found to have the color (yellow) and absorption spectrum consistent with it being a FAD-containing protein. Furthermore, it was demonstrated to have sulfhydryl oxidase activity using dithiothreitol and thioredoxin as substrates.
authors.affiliation: Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Long
authors.forename: G F
authors.initials: GF
authors.lastname: Rohrmann
authors.forename: G F
authors.initials: GF
authors.lastname: Merrill
mesh_terms: D000595:Amino Acid Sequence; D016367:Baculoviridae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence; D005182:Flavin-Adenine Dinucleotide / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames / Q000235:genetics; D010088:Oxidoreductases / Q000378:metabolism*; D016415:Sequence Alignment; D013057:Spectrum Analysis; D014764:Viral Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D050862:Oxidoreductases Acting on Sulfur Group Donors
chemical_list: D005182:Flavin-Adenine Dinucleotide; D010088:Oxidoreductases; D014764:Viral Proteins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C117170:p33 protein, baculovirus