Download MendeleyStructure and mechanism of lysosome transmembrane acetylation by HGSNAT.
Xu, R., Ning, Y., Ren, F., Gu, C., Zhu, Z., Pan, X., Pshezhetsky, A.V., Ge, J., Yu, J.(2024) Nat Struct Mol Biol 31: 1502-1508
- PubMed: 38769387
- DOI: https://doi.org/10.1038/s41594-024-01315-5
- Primary Citation of Related Structures:
8JKV, 8JL1, 8JL3, 8W4A - PubMed Abstract:
Lysosomal transmembrane acetylation of heparan sulfates (HS) is catalyzed by HS acetyl-CoA:α-glucosaminide N-acetyltransferase (HGSNAT), whose dysfunction leads to lysosomal storage diseases. The mechanism by which HGSNAT, the sole non-hydrolase enzyme in HS degradation, brings cytosolic acetyl-coenzyme A (Ac-CoA) and lysosomal HS together for N-acyltransferase reactions remains unclear. Here, we present cryogenic-electron microscopy structures of HGSNAT alone, complexed with Ac-CoA and with acetylated products. These structures explain that Ac-CoA binding from the cytosolic side causes dimeric HGSNAT to form a transmembrane tunnel. Within this tunnel, catalytic histidine and asparagine approach the lumen and instigate the transfer of the acetyl group from Ac-CoA to the glucosamine group of HS. Our study unveils a transmembrane acetylation mechanism that may help advance therapeutic strategies targeting lysosomal storage diseases.
Organizational Affiliation:
Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
