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 Conservation![]() Check, 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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