4v93

Fitted coordinates for Lumbricus terrestris hemoglobin cryo-EM complex (EMD-2627)

Loading... Status: waiting for Mol* initialization Structural highlights 4v93 is a 180 chain structure with sequence from Lumbricus terrestris. This structure supersedes the now removed PDB entries 4cyx, 4d0h and 4d0i. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GLB4_LUMTE Publication Abstract from PubMed The iron-containing hemoglobins (Hbs) are essential proteins to serve as oxygen transporters in the blood. Among various kinds of Hbs, the earthworm Hbs are the champions in carrying oxygen due to not only their large size but also the unusually high cooperativity of ligand binding. However, the cooperative oxygen binding mechanisms are still mostly unknown. Here we report the cryo-electron microscopy structure of Lumbricus terrestris Hb in its native, oxygenated state at 9.1 A resolution, showing remarkable differences from the carbon monoxide-binding X-ray structure. Our structural analysis first indicates that the cooperative ligand binding of L. terrestris Hb requires tertiary and quaternary transitions in the heme pocket and a global subunit movement facilitated by intra-ring and inter-ring contacts. Moreover, the additional sinusoidal bracelet provides the confirmation for the long-standing debate about the additional electron densities absent in the X-ray crystal structure. Structural basis for cooperative oxygen binding and bracelet-assisted assembly of Lumbricus terrestris hemoglobin.,Chen WT, Chen YC, Liou HH, Chao CY Sci Rep. 2015 Apr 21;5:9494. doi: 10.1038/srep09494. PMID:25897633 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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