Names & Taxonomy
- Uniprot ID:
- Q9UKM7
- Entry Name:
- MA1B1_HUMAN
- Status:
- reviewed
- Protein Names:
- Endoplasmic reticulum mannosyl-oligosaccharide 1,2-alpha-mannosidase (EC 3.2.1.113) (ER alpha-1,2-mannosidase) (ER mannosidase 1) (ERMan1) (Man9GlcNAc2-specific-processing alpha-mannosidase) (Mannosidase alpha class 1B member 1)
- Gene Names:
- MAN1B1 UNQ747/PRO1477
- Gene Names Orf:
- UNQ747/PRO1477
- Gene Names Primary:
- MAN1B1
- Organism:
- Homo sapiens (Human)
Structure
- Length:
- 699
- Sequence:
- MAACEGRRSGALGSSQSDFLTPPVGGAPWAVATTVVMYPPPPPPPHRDFISVTLSFGENYDNSKSWRRRSCWRKWKQLSRLQRNMILFLLAFLLFCGLLFYINLADHWKALAFRLEEEQKMRPEIAGLKPANPPVLPAPQKADTDPENLPEISSQKTQRHIQRGPPHLQIRPPSQDLKDGTQEEATKRQEAPVDPRPEGDPQRTVISWRGAVIEPEQGTELPSRRAEVPTKPPLPPARTQGTPVHLNYRQKGVIDVFLHAWKGYRKFAWGHDELKPVSRSFSEWFGLGLTLIDALDTMWILGLRKEFEEARKWVSKKLHFEKDVDVNLFESTIRILGGLLSAYHLSGDSLFLRKAEDFGNRLMPAFRTPSKIPYSDVNIGTGVAHPPRWTSDSTVAEVTSIQLEFRELSRLTGDKKFQEAVEKVTQHIHGLSGKKDGLVPMFINTHSGLFTHLGVFTLGARADSYYEYLLKQWIQGGKQETQLLEDYVEAIEGVRTHLLRHSEPSKLTFVGELAHGRFSAKMDHLVCFLPGTLALGVYHGLPASHMELAQELMETCYQMNRQMETGLSPEIVHFNLYPQPGRRDVEVKPADRHNLLRPETVESLFYLYRVTGDRKYQDWGWEILQSFSRFTRVPSGGYSSINNVQDPQKPEPRDKMESFFLGETLKYLFLLFSDDPNLLSLDAYVFNTEAHPLPIWTPA
- Proteomes:
- UP000005640
Subcellular location
- Subcellular Location:
- Endoplasmic reticulum membrane
Function
- Function:
- Involved in glycoprotein quality control targeting of misfolded glycoproteins for degradation. It primarily trims a single alpha-1,2-linked mannose residue from Man(9)GlcNAc(2) to produce Man(8)GlcNAc(2), but at high enzyme concentrations, as found in the ER quality control compartment (ERQC), it further trims the carbohydrates to Man(5-6)GlcNAc(2).
- Pathway:
- Protein modification; protein glycosylation.
- Catalytic Activity:
- Hydrolysis of the terminal (1->2)-linked alpha-D-mannose residues in the oligo-mannose oligosaccharide Man(9)(GlcNAc)(2).
- Cofactor:
- COFACTOR: Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
- Kinetics:
- BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=0.4 mM for Man9GlcNAc2
- Enzyme Regulation:
- ENZYME REGULATION: Inhibited by both 1-deoxymannojirimycin (dMNJ) and kifunensine.
- Active Site:
- ACT_SITE 330 330 Proton donor.
- Gene Ontology Go:
- endoplasmic reticulum
endoplasmic reticulum membrane
endoplasmic reticulum quality control compartment
extracellular vesicle
Golgi apparatus
integral component of membrane
membrane
calcium ion binding
mannosyl-oligosaccharide 1,2-alpha-mannosidase activity
cellular protein metabolic process
endoplasmic reticulum mannose trimming
ER-associated ubiquitin-dependent protein catabolic process
mannose trimming involved in glycoprotein ERAD pathway
N-glycan processing
oligosaccharide metabolic process
post-translational protein modification
protein alpha-1,2-demannosylation
protein folding
protein N-linked glycosylation via asparagine
trimming of terminal mannose on B branch - Gene Ontology Biological Process:
- cellular protein metabolic process
endoplasmic reticulum mannose trimming
ER-associated ubiquitin-dependent protein catabolic process
mannose trimming involved in glycoprotein ERAD pathway
N-glycan processing
oligosaccharide metabolic process
post-translational protein modification
protein alpha-1,2-demannosylation
protein folding
protein N-linked glycosylation via asparagine
trimming of terminal mannose on B branch - Gene Ontology Molecular Function:
- calcium ion binding
mannosyl-oligosaccharide 1,2-alpha-mannosidase activity - Gene Ontology Cellular Component:
- endoplasmic reticulum
endoplasmic reticulum membrane
endoplasmic reticulum quality control compartment
extracellular vesicle
Golgi apparatus
integral component of membrane
membrane - Keywords:
- 3D-structure
Calcium
Complete proteome
Disease mutation
Disulfide bond
Endoplasmic reticulum
Glycosidase
Hydrolase
Membrane
Mental retardation
Metal-binding
Polymorphism
Reference proteome
Signal-anchor
Transmembrane
Transmembrane helix