title: Functional analysis of a lipolytic protein encoded in phytoplasma phage based genomic island.
abstract: Wall-less bacteria known as phytoplasmas are obligate transkingdom parasites and pathogens of plants and insect vectors. These unusual bacteria possess some of the smallest genomes known among pathogenic bacteria, and have never been successfully isolated in artificial culture. Disease symptoms induced by phytoplasmas in infected plants include abnormal growth and often severe yellowing of leaves, but mechanisms involved in phytoplasma parasitism and pathogenicity are little understood. A phage based genomic island (sequence variable mosaic, SVM) in the genome of Malaysian periwinkle yellows (MPY) phytoplasma harbors a gene encoding membrane-targeted proteins, including a putative phospholipase (PL), potentially important in pathogen-host interactions. Since some phytoplasmal disease symptoms could possibly be accounted for, at least in part, by damage and/or degradation of host cell membranes, we hypothesize that the MPY phytoplasma putative PL is an active enzyme. To test this hypothesis, functional analysis of the MPY putative pl gene-encoded protein was carried out in vitro after its expression in bacterial and yeast hosts. The results demonstrated that the heterologously expressed phytoplasmal putative PL is an active lipolytic enzyme and could possibly act as a pathogenicity factor in the plant, and/or insect, host.
authors.affiliation: Institute of Biotechnology Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania.
authors.forename: Alma
authors.initials: A
authors.lastname: Gedvilaite
authors.affiliation: Nature Research Centre, Akademijos 2, Vilnius, Lithuania. Electronic address: rasa.jomantiene@yahoo.com.
authors.forename: Rasa
authors.initials: R
authors.lastname: Jomantiene
authors.affiliation: Institute of Biotechnology Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania.
authors.forename: Jonas
authors.initials: J
authors.lastname: Dabrisius
authors.affiliation: Institute of Biotechnology Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania; Nature Research Centre, Akademijos 2, Vilnius, Lithuania.
authors.forename: Milda
authors.initials: M
authors.lastname: Norkiene
authors.affiliation: Molecular Plant Pathology Laboratory, USDA-Agricultural Research Service, Beltsville, MD 20705, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Davis
mesh_terms: D001435:Bacteriophages / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D015870:Gene Expression; D010740:Phospholipases / Q000235:genetics* / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D045582:Phytoplasma / Q000821:virology*; D010935:Plant Diseases / Q000382:microbiology; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D010743:Phospholipids; D037521:Virulence Factors; D010740:Phospholipases
keywords: Phospholipase; Phytoplasma; Yeast