6HC0 image
Entry Detail
PDB ID:
6HC0
Title:
Bdellovibrio bacteriovorus DgcB FHA domain, tail complex
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2018-08-13
Release Date:
2019-08-28
Method Details:
Experimental Method:
Resolution:
1.87 Å
R-Value Free:
0.20
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:DgcB N-terminus
Chain IDs:A
Chain Length:7
Number of Molecules:1
Biological Source:Bdellovibrio bacteriovorus HD100
Polymer Type:polypeptide(L)
Description:GGDEF domain protein
Chain IDs:B, C, D, E
Chain Length:105
Number of Molecules:4
Biological Source:Bdellovibrio bacteriovorus (strain ATCC 15356 / DSM 50701 / NCIB 9529 / HD100)
Ligand Molecules
Primary Citation
Structural basis for activation of a diguanylate cyclase required for bacterial predation in Bdellovibrio.
Nat Commun 10 4086 4086 (2019)
PMID: 31501441 DOI: 10.1038/s41467-019-12051-6

Abstact

The bacterial second messenger cyclic-di-GMP is a widespread, prominent effector of lifestyle change. An example of this occurs in the predatory bacterium Bdellovibrio bacteriovorus, which cycles between free-living and intraperiplasmic phases after entering (and killing) another bacterium. The initiation of prey invasion is governed by DgcB (GGDEF enzyme) that produces cyclic-di-GMP in response to an unknown stimulus. Here, we report the structure of DgcB, and demonstrate that the GGDEF and sensory forkhead-associated (FHA) domains form an asymmetric dimer. Our structures indicate that the FHA domain is a consensus phosphopeptide sensor, and that the ligand for activation is surprisingly derived from the N-terminal region of DgcB itself. We confirm this hypothesis by determining the structure of a FHA:phosphopeptide complex, from which we design a constitutively-active mutant (confirmed via enzyme assays). Our results provide an understanding of the stimulus driving DgcB-mediated prey invasion and detail a unique mechanism of GGDEF enzyme regulation.

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Primary Citation of related structures