National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35GM144130
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM117372
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2025 タイトル: Structural insights into translocation and tailored synthesis of hyaluronan. 著者: Ireneusz Górniak / Zachery Stephens / Satchal K Erramilli / Tomasz Gawda / Anthony A Kossiakoff / Jochen Zimmer / 要旨: Hyaluronan (HA) is an essential component of the vertebrate extracellular matrix. It is a heteropolysaccharide of N-acetylglucosamine (GlcNAc) and glucuronic acid (GlcA) reaching several megadaltons ...Hyaluronan (HA) is an essential component of the vertebrate extracellular matrix. It is a heteropolysaccharide of N-acetylglucosamine (GlcNAc) and glucuronic acid (GlcA) reaching several megadaltons in healthy tissues. HA is synthesized and translocated in a coupled reaction by HA synthase (HAS). Here, structural snapshots of HAS provide insights into HA biosynthesis, from substrate recognition to HA elongation and translocation. We monitor the extension of a GlcNAc primer with GlcA, reveal the coordination of the uridine diphosphate product by a conserved gating loop and capture the opening of a translocation channel to coordinate a translocating HA polymer. Furthermore, we identify channel-lining residues that modulate HA product lengths. Integrating structural and biochemical analyses suggests an avenue for polysaccharide engineering based on finely tuned enzymatic activity and HA coordination.