3LA6

Octameric kinase domain of the E. coli tyrosine kinase Wzc with bound ADP

Summary for 3LA6

• Entry DOI: 10.2210/pdb3la6/pdb
• Descriptor: Tyrosine-protein kinase wzc, ADENOSINE-5'-DIPHOSPHATE, CALCIUM ION (3 entities in total)
• Functional Keywords: p-loop protein, nucleotide binding domain, walker a motif, bacterial protein kinase, oligomerization, intermolecular phosphorylation, exopolysaccharide synthesis, transferase
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P76387
• Total number of polymer chains: 16
• Total formula weight: 514360.72

Authors

Gruszczyk, J.,Nessler, S.,Gueguen-Chaignon, V.,Vigouroux, A.,Bechet, E.,Grangeasse, C. (deposition date: 2010-01-06, release date: 2010-08-25, Last modification date: 2023-11-01)

Primary citation

Bechet, E.,Gruszczyk, J.,Terreux, R.,Gueguen-Chaignon, V.,Vigouroux, A.,Obadia, B.,Cozzone, A.J.,Nessler, S.,Grangeasse, C.
Identification of structural and molecular determinants of the tyrosine-kinase Wzc and implications in capsular polysaccharide export
Mol.Microbiol., 77:1315-1325, 2010

PubMed Abstract: Capsular polysaccharides are well-established virulence factors of pathogenic bacteria. Their biosynthesis and export are regulated within the transmembrane polysaccharide assembly machinery by the autophosphorylation of atypical tyrosine-kinases, named BY-kinases. However, the accurate functioning of these tyrosine-kinases remains unknown. Here, we report the crystal structure of the non-phosphorylated cytoplasmic domain of the tyrosine-kinase Wzc from Escherichia coli in complex with ADP showing that it forms a ring-shaped octamer. Mutational analysis demonstrates that a conserved EX(2) RX(2) R motif involved in subunit interactions is essential for polysaccharide export. We also elucidate the role of a putative internal regulatory tyrosine and we show that BY-kinases from proteobacteria autophosphorylate on their C-terminal tyrosine cluster via a single-step intermolecular mechanism. This structure-function analysis also allows us to demonstrate that two different parts of a conserved basic region called the RK-cluster are essential for polysaccharide export and for kinase activity respectively. Based on these data, we revisit the dichotomy made between BY-kinases from proteobacteria and firmicutes and we propose a unique process of oligomerization and phosphorylation. We also reassess the function of BY-kinases in the capsular polysaccharide assembly machinery.

PubMed: 20633230
DOI: 10.1111/j.1365-2958.2010.07291.x

Experimental method

X-RAY DIFFRACTION (3.2 Å)