1lnl: Difference between revisions

[[Image:1lnl.gif|left|200px]]<br /><applet load="1lnl" size="350" color="white" frame="true" align="right" spinBox="true"  

Structure-function relationships in a molluscan hemocyanin have been investigated by determining the crystal structure of the Rapana thomasiana (gastropod) hemocyanin functional unit RtH2e in deoxygenated form at 3.38 A resolution. This is the first X-ray structure of an unit from the wall of the molluscan hemocyanin cylinder. The crystal structure of RtH2e demonstrates molecular self-assembly of six identical molecules forming a regular hexameric cylinder. This suggests how the functional units are ordered in the wall of the native molluscan hemocyanins. The molecular arrangement is stabilized by specific protomer-to-protomer interactions, which are probably typical for the functional units building the wall of the cylinders. A molecular mechanism for cooperative dioxygen binding in molluscan hemocyanins is proposed on the basis of the molecular interactions between the protomers. In particular, the deoxygenated RtH2e structure reveals a tunnel leading from two opposite sides of the molecule to the active site. The tunnel represents a possible entrance pathway for dioxygen molecules. No such tunnels have been observed in the crystal structure of the oxy-Odg, a functional unit from the Octopus dofleini (cephalopod) hemocyanin in oxygenated form.

1LNL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rapana_thomasiana Rapana thomasiana] with <scene name='pdbligand=NAG:'>NAG</scene> and <scene name='pdbligand=CU:'>CU</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LNL OCA].  

[[Category: Guthoehrlein, E W.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:34 2008''