Protein: Beta-amylase 3, chloroplastic (EC 3.2.1.2) (1,4-alpha-D-glucan maltohydrolase) (Beta-amylase 8) (Chloroplast beta-amylase) (CT-BMY) (O23553)
Organism: Arabidopsis thaliana (Mouse-ear cress)
Function: Beta-amylase activity. No alpha-amylase activity. Involved in cold resistance. Mediates the accumulation of maltose upon freezing stress, thus contributing to the protection of the photosynthetic electron transport chain. Plays a role in the circadian-regulated starch degradation and maltose metabolism in chloroplasts, especially at night. More active on phosphorylated glucan. Interacts directly with starch or other alpha-1,4-glucan.
Subcellular location: Plastid, chloroplast {ECO:0000269|PubMed:10652124, ECO:0000269|PubMed:16698902, ECO:0000269|PubMed:18390594}.
Sequence: MELTLNSSSSLIKRKDAKSSRNQESSSNNMTFAKMKPPTYQFQAKNSVKEMKFTHEKTFTPEGETLEKWEKLHVLSYPHSKNDASVPVFVMLPLDTVTMSGHLNKPRAMNASLMALKGAGVEGVMVDAWWGLVEKDGPMNYNWEGYAELIQMVQKHGLKLQVVMSFHQCGGNVGDSCSIPLPPWVLEEISKNPDLVYTDKSGRRNPEYISLGCDSVPVLRGRTPIQVYSDFMRSFRERFEGYIGGVIAEIQVGMGPCGELRYPSYPESNGTWRFPGIGEFQCYDKYMKSSLQAYAESIGKTNWGTSGPHDAGEYKNLPEDTEFFRRDGTWNSEYGKFFMEWYSGKLLEHGDQLLSSAKGIFQGSGAKLSGKVAGIHWHYNTRSHAAELTAGYYNTRNHDGYLPIAKMFNKHGVVLNFTCMEMKDGEQPEHANCSPEGLVKQVQNATRQAGTELAGENALERYDSSAFGQVVATNRSDSGNGLTAFTYLRMNKRLFEGQNWQQLVEFVKNMKEGGHGRRLSKEDTTGSDLYVGFVKGKIAENVEEAALV
InterPro domains: - IPR017853: Glycoside hydrolase superfamily (homologous_superfamily) [84-513]
- IPR018238: Glycoside hydrolase, family 14, conserved site (conserved_site) [167-175]
- IPR001371: Glycoside hydrolase, family 14B, plant (family) [245-500]
- IPR001554: Glycoside hydrolase, family 14 (family) [35-518]
Interaction partners: - 4-alpha-glucanotransferase DPE1, chloroplastic/amyloplastic
- 4-alpha-glucanotransferase DPE2
- Isoamylase 3, chloroplastic
- alpha-D-xyloside xylohydrolase
- Alpha-amylase 3, chloroplastic
- Alpha-amylase 1
- Probable alpha-amylase 2
- Phosphoglucan phosphatase LSF1, chloroplastic
- Alpha-glucan phosphorylase 2, cytosolic
- Isoamylase 2, chloroplastic
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0016787 (hydrolase activity), GO:0016798 (hydrolase activity, acting on glycosyl bonds), GO:0004553 (hydrolase activity, hydrolyzing O-glycosyl compounds), GO:0016160 (amylase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0050896 (response to stimulus), GO:0009987 (cellular process), GO:0009628 (response to abiotic stimulus), GO:0044237 (cellular metabolic process), GO:0042221 (response to chemical), GO:0006950 (response to stress), GO:0071704 (organic substance metabolic process), GO:0009056 (catabolic process), GO:0044238 (primary metabolic process), GO:0001101 (response to acid chemical), GO:0009414 (response to water deprivation), GO:0010035 (response to inorganic substance), GO:0009415 (response to water), GO:0044248 (cellular catabolic process), GO:1901700 (response to oxygen-containing compound), GO:0005975 (carbohydrate metabolic process), GO:1901575 (organic substance catabolic process), GO:0044260 (cellular macromolecule metabolic process), GO:0043170 (macromolecule metabolic process), GO:0010033 (response to organic substance), GO:1902074 (response to salt), GO:0044262 (cellular carbohydrate metabolic process), GO:0044275 (cellular carbohydrate catabolic process), GO:0009057 (macromolecule catabolic process), GO:0044264 (cellular polysaccharide metabolic process), GO:0005976 (polysaccharide metabolic process), GO:0016052 (carbohydrate catabolic process), GO:0000272 (polysaccharide catabolic process), GO:0006073 (cellular glucan metabolic process), GO:0044042 (glucan metabolic process), GO:0044247 (cellular polysaccharide catabolic process), GO:0005983 (starch catabolic process), GO:0009251 (glucan catabolic process), GO:0005982 (starch metabolic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0009536 (plastid), GO:0009507 (chloroplast), GO:0043231 (intracellular membrane-bounded organelle)