The HopPtoF locus of Pseudomonas syringae pv. tomato DC3000 encodes a type III chaperone and a cognate effector.
Type III secretion systems are highly conserved among gram-negative plant and animal pathogenic bacteria. Through the type III secretion system, bacteria inject a number of virulence proteins into the host cells. Analysis of the whole genome sequence of Pseudomonas syringae pv. tomato DC3000 strain identified a locus, named HopPtoF, that is homologous to the avirulence gene locus avrPphF in P. syringae pv. phaseolicola. The HopPtoF locus harbors two genes, ShcF(Pto) and HopF(Pto), that are preceded by a single hrp box promoter. We present evidence here to show that ShcF(Pto) and HopF(Pto) encode a type III chaperone and a cognate effector, respectively. ShcF(Pto) interacts with and stabilizes the HopF(Pto) protein in the bacterial cell. Translation of HopF(Pto) starts at a rare initiation codon ATA that limits the synthesis of the HopF(Pto) protein to a low level in bacterial cells.
Shan
Libo
L
Department of Plant Pathology, Kansas State University, Manhattan 66506-5502, USA.
Oh
Hye-sook
HS
Chen
Jianfu
J
Guo
Ming
M
Zhou
Jianmin
J
Alfano
James R
JR
Collmer
Alan
A
Jia
Xu
X
Tang
Xiaoyan
X
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D018387:Codon, Initiator / Q000235:genetics; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D014176:Protein Biosynthesis; D025941:Protein Interaction Mapping; D044224:Pseudomonas syringae / Q000235:genetics*; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D018387:Codon, Initiator; D018832:Molecular Chaperones