Cloning, Expression, Purification and Initial Analysis of a Novel Pectate Lyase P cpel1 from P hytophthora capsici

Phytophthora capsici inflicts damage on numerous crop plants by secreting a series of pectinase including pectate lyase ( PEL ). Here, we report a pectate lyase gene ( Pcpel1 ) from a genomic library of a highly virulent P . capsici strain SD 33. Pcpel1 was identified as an open reading frame of 1233 bp encoding a protein of 410 amino acids with a predicted amino‐terminal signal sequence of 21 amino acids. The predicted protein of P cpel1 has a calculated molecular mass of 43.8 kDa and a p I value of 6.8. Analysis of the amino acid sequence suggested that it was a member of the polysaccharide lyase family 1 that shows pectate lyase activity. Moreover, heterologous expression of P cpel1 in P ichia pastoris produced proteins with molecular mass 66 kDa, very likely due to differential glycosylation by the yeast. By western blotting and northern blotting analysis, P cpel1 was strongly expressed during interaction of P . capsici with the host plant, suggesting its involvement in the process of host infection. The role of P cpel1 in cell wall disassembly and host/parasite interaction is discussed.