3N3U

Crystal Structure of IbpAFic2

Summary for 3N3U

• Entry DOI: 10.2210/pdb3n3u/pdb
• Related: 3N3V
• Descriptor: Adenosine monophosphate-protein transferase ibpA, ZINC ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: fic domain, transferase
• Biological source: Histophilus somni
• Cellular location: Secreted . Protein p76 IgBP: Cell outer membrane ; Peripheral membrane protein ; Extracellular side : Q06277
• Total number of polymer chains: 1
• Total formula weight: 33796.80

Authors

Xiao, J. (deposition date: 2010-05-20, release date: 2010-07-14, Last modification date: 2024-02-21)

Primary citation

Xiao, J.,Worby, C.A.,Mattoo, S.,Sankaran, B.,Dixon, J.E.
Structural basis of Fic-mediated adenylylation.
Nat.Struct.Mol.Biol., 17:1004-1010, 2010

PubMed Abstract: The Fic family of adenylyltransferases, defined by a core HPFx(D/E)GN(G/K)R motif, consists of over 2,700 proteins found in organisms from bacteria to humans. The immunoglobulin-binding protein A (IbpA) from the bacterial pathogen Histophilus somni contains two Fic domains that adenylylate the switch1 tyrosine residue of Rho-family GTPases, allowing the bacteria to subvert host defenses. Here we present the structure of the second Fic domain of IbpA (IbpAFic2) in complex with its substrate, Cdc42. IbpAFic2-bound Cdc42 mimics the GDI-bound state of Rho GTPases, with both its switch1 and switch2 regions gripped by IbpAFic2. Mutations disrupting the IbpAFic2-Cdc42 interface impair adenylylation and cytotoxicity. Notably, the switch1 tyrosine of Cdc42 is adenylylated in the structure, providing the first structural view for this post-translational modification. We also show that the nucleotide-binding mechanism is conserved among Fic proteins and propose a catalytic mechanism for this recently discovered family of enzymes.

PubMed: 20622875
DOI: 10.1038/nsmb.1867

Experimental method

X-RAY DIFFRACTION (1.846 Å)