3UHB: HBI (R104K) CO bound

Here we present a meta-analysis of a large collection of static structures of a protein in the Protein Data Bank in order to extract the progression of structural events during protein function. We apply this strategy to the homodimeric hemoglobin HbI from Scapharca inaequivalvis. We derive a simple dynamic model describing how binding of the first ligand in one of the two chemically identical subunits facilitates a second binding event in the other partner subunit. The results of our ultrafast time-resolved crystallographic studies support this model. We demonstrate that HbI functions like a homodimeric mechanical device, such as pliers or scissors. Ligand-induced motion originating in one subunit is transmitted to the other via conserved pivot points, where the E and F' helices from two partner subunits are "bolted" together to form a stable dimer interface permitting slight relative rotation but preventing sliding.
PDB ID: 3UHBDownload
MMDB ID: 96115
PDB Deposition Date: 2011/11/3
Updated in MMDB: 2011/12
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Source Organism:
Similar Structures:
Biological Unit for 3UHB: dimeric; determined by author and by software (PISA)
Molecular Components in 3UHB
Label Count Molecule
Proteins (2 molecules)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB