Structural characterization of the RLCK family member BSK8: A pseudokinase with an unprecedented architecture

Christian Grütter, Shivakumar Sreeramulu, Guido Sessa, Daniel Rauh

Research output: Contribution to journalArticlepeer-review

Abstract

Brassinosteroid signaling kinases (BSKs) are plant-specific receptor-like cytoplasmic protein kinases involved in the brassinosteroid signaling pathway. Unlike common protein kinases, they possess a naturally occurring alanine residue at the "gatekeeper" position, as well as other sequence variations. How BSKs activate downstream proteins such as BSU1, as well as the structural consequences of their unusual sequential features, was unclear. We crystallized the catalytic domain of BSK8 and solved its structure by multiple-wavelength anomalous dispersion phasing methods to a resolution of 1.5 Å. In addition, a co-crystal structure of BSK8 with 5-adenylyl imidodiphosphate (AMP-PNP) revealed unusual conformational arrangements of the nucleotide phosphate groups and catalytic key motifs, typically not observed for active protein kinases. Sequential analysis and comparisons with known pseudokinase structures suggest that BSKs represent constitutively inactive protein kinases that regulate brassinosteroid signal transfer through an allosteric mechanism.

Original languageEnglish
Pages (from-to)4455-4467
Number of pages13
JournalJournal of Molecular Biology
Volume425
Issue number22
DOIs
StatePublished - 15 Nov 2013

Keywords

  • BR signaling kinase (BSK)
  • X-ray crystallography
  • brassinosteroid (BR) signaling
  • pseudokinase
  • receptor-like protein kinases

Fingerprint

Dive into the research topics of 'Structural characterization of the RLCK family member BSK8: A pseudokinase with an unprecedented architecture'. Together they form a unique fingerprint.

Cite this