Involved in the trimming of pre-amylopectin chains. Accelerates the crystallization of nascent amylopectin molecules during starch synthesis. ISA1 and ISA2 work exclusively together as a multimeric holoenzyme. ISA1-ISA2 removes preferentially branches that are very close to other branches. 783 MDAIKCSSSFLHHTKLNTLFSNHTFPKISAPNFKPLFRPISISAKDRRSNEAENIAVVEKPLKSDRFFISDGLPSPFGPTVRDDGVNFSVYSTNSVSATICLISLSDLRQNKVTEEIQLDPSRNRTGHVWHVFLRGDFKDMLYGYRFDGKFSPEEGHYYDSSNILLDPYAKAIISRDEFGVLGPDDNCWPQMACMVPTREEEFDWEGDMHLKLPQKDLVIYEMHVRGFTRHESSKIEFPGTYQGVAEKLDHLKELGINCIELMPCHEFNELEYYSYNTILGDHRVNFWGYSTIGFFSPMIRYASASSNNFAGRAINEFKILVKEAHKRGIEVIMDVVLNHTAEGNEKGPIFSFRGVDNSVYYMLAPKGEFYNYSGCGNTFNCNHPVVRQFILDCLRYWVTEMHVDGFRFDLGSIMSRSSSLWDAANVYGADVEGDLLTTGTPISCPPVIDMISNDPILRGVKLIAEAWDAGGLYQVGMFPHWGIWSEWNGKFRDVVRQFIKGTDGFSGAFAECLCGSPNLYQGGRKPWHSINFICAHDGFTLADLVTYNNKNNLANGEENNDGENHNYSWNCGEEGDFASISVKRLRKRQMRNFFVSLMVSQGVPMIYMGDEYGHTKGGNNNTYCHDNYMNYFRWDKKEEAHSDFFRFCRILIKFRDECESLGLNDFPTAKRLQWHGLAPEIPNWSETSRFVAFSLVDSVKKEIYVAFNTSHLATLVSLPNRPGYRWEPFVDTSKPSPYDCITPDLPERETAMKQYRHFLDANVYPMLSYSSIILLLSPIKDP ISOA1_ARATH T28M21.9 Isoamylase 1, chloroplastic ISA1 At2g39930