3GZ2

Crystal structure of IpgC in complex with an IpaB peptide

Summary for 3GZ2

• Entry DOI: 10.2210/pdb3gz2/pdb
• Related: 3GYZ 3GZ1
• Descriptor: Chaperone protein ipgC, Invasin ipaB, GLYCEROL, ... (5 entities in total)
• Functional Keywords: tetratricopeptide repeat, tpr, chaperone, chaperone binding region, virulence, secreted, transmembrane
• Biological source: Shigella flexneri; More
• Cellular location: Cytoplasm: P0A2U4; Secreted: P18011
• Total number of polymer chains: 3
• Total formula weight: 42977.31

Authors

Lokareddy, R.K.,Lunelli, M.,Kolbe, M. (deposition date: 2009-04-06, release date: 2010-04-21, Last modification date: 2023-11-01)

Primary citation

Lokareddy, R.K.,Lunelli, M.,Eilers, B.,Wolter, V.,Kolbe, M.
Combination of two separate binding domains defines stoichiometry between type III secretion system chaperone IpgC and translocator protein IpaB
J.Biol.Chem., 285:39965-39975, 2010

PubMed Abstract: Type III secretion systems (TTSSs) utilized by enteropathogenic bacteria require the presence of small, acidic virulence-associated chaperones for effective host cell infection. We adopted a combination of biochemical and cellular techniques to define the chaperone binding domains (CBDs) in the translocators IpaB and IpaC associated with the chaperone IpgC from Shigella flexneri. We identified a novel CBD in IpaB and furthermore precisely mapped the boundaries of the CBDs in both translocator proteins. In IpaC a single binding domain associates with IpgC. In IpaB, we show that the binding of the newly characterized CBD is essential in maintaining the ternary arrangement of chaperone-translocator complex. This hitherto unknown function is reflected in the co-crystal structure as well, with an IpgC dimer bound to an IpaB fragment comprising both CBDs. Moreover, in the absence of this novel CBD the IpaB/IpgC complex aggregates. This dual-recognition of a domain in the protein by the chaperone in facilitating the correct chaperone-substrate organization describes a new function for the TTSS associated chaperone-substrate complexes.

PubMed: 20937829
DOI: 10.1074/jbc.M110.135616

Experimental method

X-RAY DIFFRACTION (2.65 Å)