Identifying the determinants in the equatorial domain of Buchnera GroEL implicated in binding Potato leafroll virus.
Luteoviruses avoid degradation in the hemolymph of their aphid vector by interacting with a GroEL homolog from the aphid's primary endosymbiotic bacterium (Buchnera sp.). Mutational analysis of GroEL from the primary endosymbiont of Myzus persicae (MpB GroEL) revealed that the amino acids mediating binding of Potato leafroll virus (PLRV; Luteoviridae) are located within residues 9 to 19 and 427 to 457 of the N-terminal and C-terminal regions, respectively, of the discontinuous equatorial domain. Virus overlay assays with a series of overlapping synthetic decameric peptides and their derivatives demonstrated that R13, K15, L17, and R18 of the N-terminal region and R441 and R445 of the C-terminal region of the equatorial domain of GroEL are critical for PLRV binding. Replacement of R441 and R445 by alanine in full-length MpB GroEL and in MpB GroEL deletion mutants reduced but did not abolish PLRV binding. Alanine substitution of either R13 or K15 eliminated the PLRV-binding capacity of the other and those of L17 and R18. In the predicted tertiary structure of GroEL, the determinants mediating virus binding are juxtaposed in the equatorial plain.
Hogenhout
S A
SA
Plant Research International, 6700 AA Wageningen, 6709 PD Wageningen, The Netherlands.
van der Wilk
F
F
Verbeek
M
M
Goldbach
R W
RW
van den Heuvel
J F
JF
D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001042:Aphids / Q000382:microbiology*; D001665:Binding Sites; D020635:Buchnera / Q000235:genetics / Q000378:metabolism*; D018834:Chaperonin 60 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D017793:Luteovirus / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000821:virology
D000596:Amino Acids; D018834:Chaperonin 60; D000409:Alanine