The methylotrophic yeast, Pichia pastoris, has been used as a protein expression system to express over 500 heterologous proteins. P. pastoris provides many advantages over other organisms that have been utilized for this purpose. In this project, we developed a new host/selectable marker and auxotrophic strains of P. pastoris based on methionine biosynthesis to increase P. pastoris's versatility as a host for homologous protein expression. This was accomplished by selecting for a yeast that is deficient in methionine biosynthesis, P. pastoris (yJC239), and gene complementation through transformation with a genomic DNA library.
Bioinformatics show that the P. pastor is MET gene has 54% amino acid identity with 68% similarity to the S. cerevisiae MET2 gene, which codes for homoserine O-transacetylase. We have constructed expression vectors for intracellular and extracellular expression of proteins with the MET2 marker and have also constructed strains with various auxotrophs including me/2.
","abstract_html":"<p>The methylotrophic yeast, Pichia pastoris, has been used as a protein expression system to express over 500 heterologous proteins. P. pastoris provides many advantages over other organisms that have been utilized for this purpose. In this project, we developed a new host/selectable marker and auxotrophic strains of P. pastoris based on methionine biosynthesis to increase P. pastoris's versatility as a host for homologous protein expression. This was accomplished by selecting for a yeast that is deficient in methionine biosynthesis, P. pastoris (yJC239), and gene complementation through transformation with a genomic DNA library.</p> <p>Bioinformatics show that the P. pastor is MET gene has 54% amino acid identity with 68% similarity to the S. cerevisiae MET2 gene, which codes for homoserine O-transacetylase. We have constructed expression vectors for intracellular and extracellular expression of proteins with the MET2 marker and have also constructed strains with various auxotrophs including me/2.</p>","abstract_has_math":false,"creators":["Thor, Der"],"institution":null,"degree_name":"Master of Science (M.S.)","degree_level":"Thesis - Pacific Access Restricted","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":["Geoff Lin-Cereghino"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-01-01T08:00:00Z","date_published":"2002-01-01T08:00:00Z","updated_at":"2026-07-24T05:36:28Z","subjects":["Fungal gene expression","Recombinant proteins","Pichia pastoris","Yeast","Life Sciences"],"languages":[],"rights":[],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://scholarlycommons.pacific.edu/uop_etds/570","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Geoff Lin-Cereghino"]},{"key":"dc:creator","label":"Author","values":["Thor, Der"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2018-06-29T09:01:03Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - Pacific Access Restricted"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (M.S.)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Fungal gene expression","Recombinant proteins","Pichia pastoris","Yeast","Life Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarlycommons.pacific.edu/uop_etds/570"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The methylotrophic yeast, Pichia pastoris, has been used as a protein expression system to express over 500 heterologous proteins. P. pastoris provides many advantages over other organisms that have been utilized for this purpose. In this project, we developed a new host/selectable marker and auxotrophic strains of P. pastoris based on methionine biosynthesis to increase P. pastoris's versatility as a host for homologous protein expression. This was accomplished by selecting for a yeast that is deficient in methionine biosynthesis, P. pastoris (yJC239), and gene complementation through transformation with a genomic DNA library.
Bioinformatics show that the P. pastor is MET gene has 54% amino acid identity with 68% similarity to the S. cerevisiae MET2 gene, which codes for homoserine O-transacetylase. We have constructed expression vectors for intracellular and extracellular expression of proteins with the MET2 marker and have also constructed strains with various auxotrophs including me/2.
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Bioinformatics show that the P. pastor is MET gene has 54% amino acid identity with 68% similarity to the S. cerevisiae MET2 gene, which codes for homoserine O-transacetylase. We have constructed expression vectors for intracellular and extracellular expression of proteins with the MET2 marker and have also constructed strains with various auxotrophs including me/2.
"],"dc:identifier":["https://scholarlycommons.pacific.edu/uop_etds/570"],"dc:rights":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:source":["61"],"dc:subject":["Fungal gene expression","Recombinant proteins","Pichia pastoris","Yeast","Life Sciences"],"dc:title":["Cloning and characterization of MET2 in Pichia pastoris"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Thesis - Pacific Access Restricted"],"thesis:degree_name":["Master of Science (M.S.)"]},"updated_at":"2026-07-24T05:36:28Z"}