1tp8: Difference between revisions

Revision as of 16:15, 21 February 2008

CRYSTAL STRUCTURE OF A GALACTOSE SPECIFIC LECTIN FROM ARTOCARPUS HIRSUTA IN COMPLEX WITH METHYL-a-D-GALACTOSE

OverviewOverview

Based on their carbohydrate specificity, the jacalin family of lectins can be divided into two groups: galactose-specific and mannose-specific. The former are cytoplasmic proteins, whereas the latter are localized in the storage vacuoles of cells. It has been proposed that the post-translational modification in some of the lectins that splits their polypeptide chains into two may be crucial for galactose specificity. The mannose-specific members of the family are single-chain proteins that lack the above modification. Although the galactose-specific and the mannose-specific jacalin-type lectins differ in their sequences, they share a common fold: the beta-prism I fold, which is characteristic of Moraceae plant lectins. Here, two crystal structures of a jacalin-related lectin from Artocarpus hirsuta, which is specific for galactose, in complex with methyl-alpha-D-galactose are reported. The lectin crystallized in two orthorhombic forms and one hexagonal form under similar conditions. The crystals had an unusually high solvent content. The structure was solved using the molecular-replacement method using the jacalin structure as a search model. The two orthorhombic forms were refined using data to 2.5 and 3.0 A resolution, respectively. The structures of the A. hirsuta lectin and jacalin are identical. In orthorhombic form I the crystal packing provides three different micro-environments for sugar binding in the same crystal. The observed difference in the specificity for oligosaccharides between the A. hirsuta lectin and jacalin could only be explained based on differences in the molecular associations in the packing and variation of the C-terminal length of the beta-chain. The observed insecticidal activity of A. hirsuta lectin may arise from its similar fold to domain II of the unrelated delta-endotoxin from Bacillus thuringiensis.

About this StructureAbout this Structure

1TP8 is a Protein complex structure of sequences from Artocarpus hirsutus with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Two orthorhombic crystal structures of a galactose-specific lectin from Artocarpus hirsuta in complex with methyl-alpha-D-galactose., Rao KN, Suresh CG, Katre UV, Gaikwad SM, Khan MI, Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1404-12. Epub 2004, Jul 21. PMID:15272163

Page seeded by OCA on Thu Feb 21 15:15:57 2008

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-[[Image:1tp8.gif|left|200px]]<br /><applet load="1tp8" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1tp8.gif|left|200px]]<br /><applet load="1tp8" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1tp8, resolution 3.0&Aring;" />
 '''CRYSTAL STRUCTURE OF A GALACTOSE SPECIFIC LECTIN FROM ARTOCARPUS HIRSUTA IN COMPLEX WITH METHYL-a-D-GALACTOSE'''<br />
 ==Overview==
-Based on their carbohydrate specificity, the jacalin family of lectins can, be divided into two groups: galactose-specific and mannose-specific. The, former are cytoplasmic proteins, whereas the latter are localized in the, storage vacuoles of cells. It has been proposed that the, post-translational modification in some of the lectins that splits their, polypeptide chains into two may be crucial for galactose specificity. The, mannose-specific members of the family are single-chain proteins that lack, the above modification. Although the galactose-specific and the, mannose-specific jacalin-type lectins differ in their sequences, they, share a common fold: the beta-prism I fold, which is characteristic of, Moraceae plant lectins. Here, two crystal structures of a jacalin-related, lectin from Artocarpus hirsuta, which is specific for galactose, in, complex with methyl-alpha-D-galactose are reported. The lectin, crystallized in two orthorhombic forms and one hexagonal form under, similar conditions. The crystals had an unusually high solvent content., The structure was solved using the molecular-replacement method using the, jacalin structure as a search model. The two orthorhombic forms were, refined using data to 2.5 and 3.0 A resolution, respectively. The, structures of the A. hirsuta lectin and jacalin are identical. In, orthorhombic form I the crystal packing provides three different, micro-environments for sugar binding in the same crystal. The observed, difference in the specificity for oligosaccharides between the A. hirsuta, lectin and jacalin could only be explained based on differences in the, molecular associations in the packing and variation of the C-terminal, length of the beta-chain. The observed insecticidal activity of A. hirsuta, lectin may arise from its similar fold to domain II of the unrelated, delta-endotoxin from Bacillus thuringiensis.
+Based on their carbohydrate specificity, the jacalin family of lectins can be divided into two groups: galactose-specific and mannose-specific. The former are cytoplasmic proteins, whereas the latter are localized in the storage vacuoles of cells. It has been proposed that the post-translational modification in some of the lectins that splits their polypeptide chains into two may be crucial for galactose specificity. The mannose-specific members of the family are single-chain proteins that lack the above modification. Although the galactose-specific and the mannose-specific jacalin-type lectins differ in their sequences, they share a common fold: the beta-prism I fold, which is characteristic of Moraceae plant lectins. Here, two crystal structures of a jacalin-related lectin from Artocarpus hirsuta, which is specific for galactose, in complex with methyl-alpha-D-galactose are reported. The lectin crystallized in two orthorhombic forms and one hexagonal form under similar conditions. The crystals had an unusually high solvent content. The structure was solved using the molecular-replacement method using the jacalin structure as a search model. The two orthorhombic forms were refined using data to 2.5 and 3.0 A resolution, respectively. The structures of the A. hirsuta lectin and jacalin are identical. In orthorhombic form I the crystal packing provides three different micro-environments for sugar binding in the same crystal. The observed difference in the specificity for oligosaccharides between the A. hirsuta lectin and jacalin could only be explained based on differences in the molecular associations in the packing and variation of the C-terminal length of the beta-chain. The observed insecticidal activity of A. hirsuta lectin may arise from its similar fold to domain II of the unrelated delta-endotoxin from Bacillus thuringiensis.
 ==About this Structure==
-TP8 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Artocarpus_hirsutus Artocarpus hirsutus] with AMG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1TP8 OCA].
+TP8 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Artocarpus_hirsutus Artocarpus hirsutus] with <scene name='pdbligand=AMG:'>AMG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TP8 OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Artocarpus hirsutus]]
 [[Category: Protein complex]]
-[[Category: Gaikwad, S.M.]]
+[[Category: Gaikwad, S M.]]
-[[Category: Katre, U.V.]]
+[[Category: Katre, U V.]]
-[[Category: Khan, M.I.]]
+[[Category: Khan, M I.]]
-[[Category: Rao, K.N.]]
+[[Category: Rao, K N.]]
-[[Category: Suresh, C.G.]]
+[[Category: Suresh, C G.]]
 [[Category: AMG]]
 [[Category: -prism i fold]]
@@ Line 29: / Line 29: @@
 [[Category: x-ray crystallography]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 03:28:51 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:15:57 2008''