GBE1 supplies the branching reaction during glycogen synthesis. The human functional and structural studies support this catalytic role; disease-associated loss of branching explains polyglucosan accumulation without requiring a second core activity (PMID:8613547(https://pubmed.ncbi.nlm.nih.gov/8613547/), PMID:26199317(https://pubmed.ncbi.nlm.nih.gov/26199317/)). The human 38–700 crystallization construct is distinct from the current 702-residue canonical product.
The STBD1 association remains a positive biochemical observation, while its downstream mechanism for GBE1 is unresolved. The viral NSP16 screen pair supports a bounded enzyme-binding classification, not an infected-cell role (PMID:24837458(https://pubmed.ncbi.nlm.nih.gov/24837458/), PMID:36217029(https://pubmed.ncbi.nlm.nih.gov/36217029/)).
Two original urinary-vesicle datasets identify GBE1. These support contextual fraction occurrence alongside its primary cytosolic role; they do not establish extracellular catalysis or vesicle topology (PMID:19056867(https://pubmed.ncbi.nlm.nih.gov/19056867/), PMID:23533145(https://pubmed.ncbi.nlm.nih.gov/23533145/)). Cation binding remains unresolved. The source-specific evidence and limits are in the source guide and selected external evidence.
A separate oligosaccharide-binding assertion now records the observed noncatalytic pocket, while the branching-enzyme core remains singular (PMID:26199317(https://doi.org/10.1093/hmg/ddv280)). Human cDNA complementation independently supports branching function (PMID:8463281(https://pubmed.ncbi.nlm.nih.gov/8463281/)). UniProt assigns a monomer; this is distinguished from a newly measured solution assembly.
The NSP16 interaction retains its positive HIS3 evidence and partner-class refinement. STBD1 association remains positive despite removal of its uninformative generic term. Cation binding remains unresolved after the documented domain, structural-text and UniProt checks; a speculative experiment is withdrawn because missing mapping grounds do not establish a biological knowledge gap.
The selected source evidence now exposes exact table fields, original download links and PAINT ancestry. The provenance index points to the immutable lossless records rather than repeating the raw API matrix.