1ps3

From Proteopedia

Golgi alpha-mannosidase II in complex with kifunensine

PDB ID 1ps3

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Structural highlights

1ps3 is a 1 chain structure with sequence from Drosophila melanogaster. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.8Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

MAN2_DROME Catalyzes the first committed step in the biosynthesis of complex N-glycans. It controls conversion of high mannose to complex N-glycans; the final hydrolytic step in the N-glycan maturation pathway (By similarity).

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Mannosidases are key enzymes in the eukaryotic N-glycosylation pathway. These enzymes fall into two broad classes (I and II) and are characteristically different in catalytic mechanism, sequence, and structure. Kifunensine is an alkaloid that is a strong inhibitor against class I alpha-mannosidases but is only a weak inhibitor against class II alpha-mannosidases. In this paper, the 1.80 A resolution crystal structure of kifunensine bound to Drosophila melanogaster Golgi alpha-mannosidase II (dGMII) is presented. Kifunensine adopts a (1,4)B boat conformation in the class II dGMII, which contrasts the (1)C(4) chair conformation seen in class I human endoplasmic reticulum alpha1,2 mannosidase (hERMI, PDB ). The observed conformations are higher in conformational energy than the global minimum (4)C(1) conformation, although the conformation in hERMI is closer to the minimum, as supported by an energy calculation. Differing conformations of 1-deoxymannojirimycin were also observed: a (4)C(1) and (1)C(4) conformation in dGMII and hERMI, respectively. Thus, these two alpha-mannosidase classes distort these inhibitors in distinct manners. This is likely indicative of the binding characteristics of the two different catalytic mechanisms of these enzymes.

Comparison of kifunensine and 1-deoxymannojirimycin binding to class I and II alpha-mannosidases demonstrates different saccharide distortions in inverting and retaining catalytic mechanisms.,Shah N, Kuntz DA, Rose DR Biochemistry. 2003 Dec 2;42(47):13812-6. PMID:14636047^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Shah N, Kuntz DA, Rose DR. Comparison of kifunensine and 1-deoxymannojirimycin binding to class I and II alpha-mannosidases demonstrates different saccharide distortions in inverting and retaining catalytic mechanisms. Biochemistry. 2003 Dec 2;42(47):13812-6. PMID:14636047 doi:10.1021/bi034742r