PDBsum entry 3a9m

Oxygen transport

PDB id

3a9m

Loading ...

Contents

			Protein chain

					152 a.a. *

			Ligands

					HEM-CMO

			Waters ×316

* Residue conservation analysis

PDB id:

3a9m

Links

Name:

Oxygen transport

Title:

Crystal structure of a hemoglobin component v from propsilocerus akamusi (ph9.0 coordinates)

Structure:

Hemoglobin v. Chain: a

Source:

Tokunagayusurika akamusi. Organism_taxid: 28383. Tissue: larval hemolymph

Resolution:

1.80Å

R-factor:

0.206

R-free:

0.232

Authors:

T.Kuwada,T.Hasegawa,T.Takagi,F.Shishikura

Key ref:

T.Kuwada et al. (2010). pH-dependent structural changes in haemoglobin component V from the midge larva Propsilocerus akamusi (Orthocladiinae, Diptera). Acta Crystallogr D Biol Crystallogr, 66, 258-267. PubMed id: 20179337

Date:

30-Oct-09

Release date:

23-Mar-10

PROCHECK

	Headers

	References

Protein chain

Q7M422 (Q7M422_9DIPT) - Hemoglobin V from Tokunagayusurika akamusi

Seq: Struc:					152 a.a. 152 a.a.

Key:

PfamA domain

Secondary structure

CATH domain

	Acta Crystallogr D Biol Crystallogr 66:258-267 (2010)
PubMed id: 20179337

pH-dependent structural changes in haemoglobin component V from the midge larva Propsilocerus akamusi (Orthocladiinae, Diptera).
T.Kuwada, T.Hasegawa, T.Takagi, I.Sato, F.Shishikura.

ABSTRACT

Haemoglobin component V (Hb V) from the midge larva Propsilocerus akamusi exhibits oxygen affinity despite the replacement of HisE7 and a pH-dependence of its functional properties. In order to understand the contribution of the distal residue to the ligand-binding properties and the pH-dependent structural changes in this insect Hb, the crystal structure of Hb V was determined under five different pH conditions. Structural comparisons of these Hb structures indicated that at neutral pH ArgE10 contributes to the stabilization of the haem-bound ligand molecule as a functional substitute for the nonpolar E7 residue. However, ArgE10 does not contribute to stabilization at acidic and alkaline pH because of the swinging movement of the Arg side chain under these conditions. This pH-dependent behaviour of Arg results in significant differences in the hydrogen-bond network on the distal side of the haem in the Hb V structures at different pH values. Furthermore, the change in pH results in a partial movement of the F helix, considering that coupled movements of ArgE10 and the F helix determine the haem location at each pH. These results suggested that Hb V retains its functional properties by adapting to the structural changes caused by amino-acid replacements.

Literature references that cite this PDB file's key reference

PubMed id

Reference

21543852

T.Kuwada, T.Hasegawa, T.Takagi, T.Sakae, I.Sato, and F.Shishikura (2011).
Involvement of the distal Arg residue in Cl⁻ binding of midge larval haemoglobin.

Acta Crystallogr D Biol Crystallogr, 67, 488-495.

PDB codes:

3arj 3ark 3arl

The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.