UniProt:Q0DDE3 SSII-3

chain
  • transit peptide:1-16
  • chain:17-810
checksum 9676434321EAFE72
comment
  • FUNCTION Plays an important role during endosperm starch synthesis. Determines the type of amylopectin structure of starch grain. Synthesizes long B1 amylopectin chains by elongating short A and B1 chains, independently of the other soluble starch synthases. Barely active in japonica subspecies.CATALYTIC ACTIVITY [(1->4)-alpha-D-glucosyl](n) + ADP-alpha-D-glucose = [(1->4)-alpha-D-glucosyl](n+1) + ADP + H(+)PATHWAY Glycan biosynthesis; starch biosynthesis.SUBCELLULAR LOCATION Amyloplast or chloroplast, granule-bound and soluble.TISSUE SPECIFICITY Expressed most exclusively in endosperm.DEVELOPMENTAL STAGE Expressed in developing caryopsis at 5 to 15 days after flowering. Expressed exclusively in the endosperm at 5 to 10 days after flowering.MISCELLANEOUS Increased activity due to variations in subspecies indica is associated with the synthesis of the L-type amylopectin, which contains much lower proportion of short amylopectin chains than the S-type amylopectin found in most japonica varieties. The difference in amylopectin chain composition explains why starch from japonica subspecies has a lower gelatinisation temperature than starch from indica subspecies.SIMILARITY Belongs to the glycosyltransferase 1 family. Bacterial/plant glycogen synthase subfamily.
created [InstanceEdit:1164949] Wu, Guanming, 2010-12-11
crossReference
databaseName UniProt
dbId 1158127
description
  • recommendedName: Soluble starch synthase 2-3, chloroplastic/amyloplastic ecNumber: 2.4.1.21 alternativeName: Soluble starch synthase II-3 alternativeName: Starch synthase IIa
displayName UniProt:Q0DDE3 SSII-3
geneName
  • SSII-3
  • ALK
  • Os06g0229800
  • LOC_Os06g12450
  • P0525F01.23
identifier Q0DDE3
isSequenceChanged false
keyword
  • Amyloplast
  • Chloroplast
  • Direct protein sequencing
  • Glycosyltransferase
  • Plastid
  • Reference proteome
  • Starch biosynthesis
  • Transferase
  • Transit peptide
modified [InstanceEdit:9852000] Weiser, Joel, 2023-11-03
name
  • SSII-3
referenceDatabase [ReferenceDatabase:2] UniProt
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • SSY23_ORYSJ
  • Q5DWW9
  • Q5DWX1
  • Q67X47
  • Q6TDS3
  • Q944W5
sequenceLength 810
species [Species:1250427] Oryza sativa subsp. japonica
url http://purl.uniprot.org/uniprot/Q0DDE3