6TI2

Structure of the Ustilago maydis chorismate mutase 1 in complex with KWL1-b from Zea mays

Summary for 6TI2

• Entry DOI: 10.2210/pdb6ti2/pdb
• Descriptor: Chromosome 16, whole genome shotgun sequence, Ripening-related protein 3 (3 entities in total)
• Functional Keywords: kiwellin, chorismate mutase, smut, infection, cell invasion
• Biological source: Ustilago maydis 521; More
• Total number of polymer chains: 4
• Total formula weight: 104643.64

Authors

Altegoer, F.,Bange, G. (deposition date: 2019-11-21, release date: 2020-05-06, Last modification date: 2024-10-23)

Primary citation

Altegoer, F.,Weiland, P.,Giammarinaro, P.I.,Freibert, S.A.,Binnebesel, L.,Han, X.,Lepak, A.,Kahmann, R.,Lechner, M.,Bange, G.
The two paralogous kiwellin proteins KWL1 and KWL1-b from maize are structurally related and have overlapping functions in plant defense.
J.Biol.Chem., 295:7816-7825, 2020

PubMed Abstract: Many plant-pathogenic bacteria and fungi deploy effector proteins that down-regulate plant defense responses and reprogram plant metabolism for colonization and survival Kiwellin (KWL) proteins are a widespread family of plant-defense proteins that target these microbial effectors. The KWL1 protein from maize (corn, ) specifically inhibits the enzymatic activity of the secreted chorismate mutase Cmu1, a virulence-promoting effector of the smut fungus In addition to KWL1, 19 additional KWL paralogs have been identified in maize. Here, we investigated the structure and mechanism of the closest KWL1 homolog, KWL1-b (ZEAMA_GRMZM2G305329). We solved the Cmu1-KWL1-b complex to 2.75 Å resolution, revealing a highly symmetric Cmu1-KWL1-b heterotetramer in which each KWL1-b monomer interacts with a monomer of the Cmu1 homodimer. The structure also revealed that the overall architecture of the heterotetramer is highly similar to that of the previously reported Cmu1-KWL1 complex. We found that upon infection of , KWL1-b is expressed at significantly lower levels than KWL1 and exhibits differential tissue-specific expression patterns. We also show that KWL1-b inhibits Cmu1 activity similarly to KWL1. We conclude that KWL1 and KWL1-b are part of a redundant defense system that tissue-specifically targets Cmu1. This notion was supported by the observation that both KWL proteins are carbohydrate-binding proteins with distinct and likely tissue-related specificities. Moreover, binding by Cmu1 modulated the carbohydrate-binding properties of both KWLs. These findings indicate that KWL proteins are part of a spatiotemporally coordinated, plant-wide defense response comprising proteins with overlapping activities.

PubMed: 32350112
DOI: 10.1074/jbc.RA119.012207

Experimental method

X-RAY DIFFRACTION (2.75 Å)