LOTP, A NOVEL Ca. Liberibacter asiaticus GROEL INTERACTING PROTEIN

FLAVIA LOTO; GONZALEZ, CLAUDIO F.; LORCA, GRACIELA L.; PADGETT, KAYLIE A.

Congreso; International Citrus Congress; 2016

Clibasia_03135 is a highly induced gene in CLas mRNA samples obtained from infectedcitrus plants. The expression of this gene is undetectable in samples obtainedfrom CLas infected psyllids. Theencoded protein could playa n important role in helping the bacteria to thrivein the harsh condition of the plant phloem. To evaluate  the biochemical characteristics and itsbiological significance we have cloned the gene and purified the encodedprotein (re-named LotP). Co-immunoprecipitation assays allowed us to identifyGroEL chaperon as the main interacting protein. The specific interactionbetween LotP and GroEL was confirmed by using a two hybrid system inEscherichia coli. LotP  is a dimer insolution with a native  molecular weigthof 44 Kd and ATPase activity in vitro. It display remarkable structuralhomology but no sequence conservation with the amino-terminal región of the LONpeptidase. Consequently, LotP was systemically annotated as an ATP dependentaminopeptidase composed by 6 units of 90 KD each. The results obtained in ouranalysis allow us to define that LotP belongs to a different family of proteinsinvolved in protein refolding. LotP protein is the first member of this largefamily to be biochemically characterized. These proteins modulate the activityof stress proteins by direct physical contact depending on the stressconditions present in the enviroment.