Protein
Isoamylase 1, chloroplastic
Organism
Oryza sativa subsp. japonica
Function
Starch-debranching enzyme involved in amylopectin biosynthesis in endosperm. Functions by removing excess branches or improper branches that interfere with the formation of double helices of the cluster chains of amylopectin and crystallization of starch (PubMed:10517831, PubMed:15618430, PubMed:16953433, PubMed:21436381). Works as ISA1 homooligomer or together with ISA2 as heterooligomer. The heterooligomer ISA1 and ISA2 possesses higher affinity than the ISA1 homooligomer for various branched polyglucans in vitro, but no marked differences exist in chain preferences for debranching of amylopectin and phytoglycogen between these forms (PubMed:16953433, PubMed:21436381).
Similarity
Belongs to the glycosyl hydrolase 13 family.
Sequence
MASLPHCLSARPLVVAAAPGRPGPGPGPWLRGGARRRNAAFSAGNAGRRVGLRRSVASAVEVGVGEDEEEGVEEEEEEVEAVVMPERYALGGACRVLAGMPAPLGATALDGGVNFAVYSAGASAASLCLFTPDDLEADEVTEEVPLDPLFNRTGNVWHVFIEGELHNMLYGYRFDGMFAPHCGQYFDVSNVVVDPYAKAVISRGEYGVPGPGGDCWPQMAGMIPLPYSTFDWQGDLPLRYPQKDLVIYEMHLRGFTKHSSSNVEHPGTYIGAISKLDYLKELGVNCVELMPCHEFNELEYFSCSSKMNFWGYSTINFFSPMIRYSSGGIRNCGRDAINEFKTFVREAHKRGIEVIMDVVFNHTAEGNEKGPILSFRGIDNSTYYMLAPKGEFYNYSGCGNTFNCNHPVVREFIVDCLRYWVTEMHVDGFRFDLASIMTRGCSLWDPVNVYGSPVEGDMTTTGTPLATPPLIDMISNDPILGDVKLIAEAWDAGGLYQVGQFPHWKIWSEWNGKYRDIVRQFIKGTDGFAGGFAECLCGSPHLYQAGGRKPWHSINFVCAHDGFTLADLVTYNKKYNSSNGEDNRDGENHNLSWNCGEEGEFAGLSVKRLRKRQMRNFFVSLMVSQGVPMFYMGDEYGHTKGGNNNTYCHDHYVNYFRWDKKEESSDLQRFCSLMTKFRKQCESLGLADFPTAQRLHWHGHQPGKPDWSETSRFVAFSTKDETKGEIYVAFNASHLPAVVGLPERPGYRWEPLVDTGKPAPYDFLTDDLPDRAHAVHLFSHFLNSNLYPMLSYSSIILELQPDD