Kinase-interacting domains of the HopAB family of Type III Effector proteins
HopAB family members are type III effector proteins that are secreted by the plant pathogen Pseudomonas syringae into the host plant to inhibit its immune system and facilitate the spread of the pathogen. AvrPtoB, also called HopAB3, is the best studied member of the family. It suppresses host basal defenses by interfering with PAMP (pathogen-associated molecular signature)-triggered immunity (PTI) through binding and inhibiting BAK1, a kinase which serves to activate defense signaling. It also recognizes the kinase Pto to activate effector-triggered immunity (ETI). AvrPtoB contains an N-terminal region that contains two kinase-interacting domains (KID) and a C-terminal E3 ligase domain. The first KID recognizes the PTI-associated kinase Bti9 as well as Pto, and is referred to as the Pto-binding domain (PID). The second KID interacts with BAK1 and FLS2, which are leucine-rich repeat-containing receptor-like kinases, and is called the BAK1-interacting domain (BID). This family also contains a unique member, HopPmaL, which is shorter and lacks the C-terminal E3 ligase domain.
Feature 1:kinase binding site [polypeptide binding site]
Evidence:
Comment:highlights reflect the overlapping interactions of the two kinase-binding domains with their respective targets
Comment:The two kinase-binding domains of AvrPtoB bind their respective targets, Pto and BAK1, in different orientations with a few overlapping interactions.
Structure:3TL8: Pseudomonas syringae AvrPtoB BID binds the kinase BAK1; contacts at 4A.
Jiyao W et al.(2023). "The conserved domain database in 2023.",