1o7d
The structure of the bovine lysosomal a-mannosidase suggests a novel mechanism for low pH activationThe structure of the bovine lysosomal a-mannosidase suggests a novel mechanism for low pH activation
Structural highlights
DiseaseMA2B1_BOVIN Note=Defects in MAN2B1 are the cause of lysosomal alpha-mannosidosis (AM). AM is a lysosomal storage disease characterized by accumulation of unbranched oligosaccharide chains. The disease manifests itself by head tremor, aggressive tendency, ataxia, failure to thrive, and early death. FunctionMA2B1_BOVIN Necessary for the catabolism of N-linked carbohydrates released during glycoprotein turnover. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedLysosomal alpha-mannosidase (LAM: EC 3.2.1.24) belongs to the sequence-based glycoside hydrolase family 38 (GH38). Two other mammalian GH38 members, Golgi alpha-mannosidase II (GIIAM) and cytosolic alpha-mannosidase, are expressed in all tissues. In humans, cattle, cat and guinea pig, lack of lysosomal alpha-mannosidase activity causes the autosomal recessive disease alpha-mannosidosis. Here, we describe the three-dimensional structure of bovine lysosomal alpha-mannosidase (bLAM) at 2.7A resolution and confirm the solution state dimer by electron microscopy. We present the first structure of a mammalian GH38 enzyme that offers indications for the signal areas for mannose phosphorylation, suggests a previously undetected mechanism of low-pH activation and provides a template for further biochemical studies of the family 38 glycoside hydrolases as well as lysosomal transport. Furthermore, it provides a basis for understanding the human form of alpha-mannosidosis at the atomic level. The atomic coordinates and structure factors have been deposited in the Protein Data Bank (accession codes 1o7d and r1o7dsf). The structure of bovine lysosomal alpha-mannosidase suggests a novel mechanism for low-pH activation.,Heikinheimo P, Helland R, Leiros HK, Leiros I, Karlsen S, Evjen G, Ravelli R, Schoehn G, Ruigrok R, Tollersrud OK, McSweeney S, Hough E J Mol Biol. 2003 Mar 28;327(3):631-44. PMID:12634058[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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