7TA2

Crystal structure of the human sperm-expressed surface protein SPACA6

7TA2 の概要

• エントリーDOI: 10.2210/pdb7ta2/pdb
• 分子名称: Sperm acrosome membrane-associated protein 6, BROMIDE ION (3 entities in total)
• 機能のキーワード: gamete fusion, sperm, fusogen, fertilization, unknown function
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27838.96

構造登録者

Vance, T.D.R.,Yip, P.,Jimenez, E.,Uson, I.,Lee, J.E. (登録日: 2021-12-20, 公開日: 2022-08-31, 最終更新日: 2024-10-23)

主引用文献

Vance, T.D.R.,Yip, P.,Jimenez, E.,Li, S.,Gawol, D.,Byrnes, J.,Uson, I.,Ziyyat, A.,Lee, J.E.
SPACA6 ectodomain structure reveals a conserved superfamily of gamete fusion-associated proteins.
Commun Biol, 5:984-984, 2022

PubMed Abstract: SPACA6 is a sperm-expressed surface protein that is critical for gamete fusion during mammalian sexual reproduction. Despite this fundamental role, little is known about how SPACA6 specifically functions. We elucidated the crystal structure of the SPACA6 ectodomain at 2.2-Å resolution, revealing a two-domain protein containing a four-helix bundle and Ig-like β-sandwich connected via a quasi-flexible linker. This structure is reminiscent of IZUMO1, another gamete fusion-associated protein, making SPACA6 and IZUMO1 founding members of a superfamily of fertilization-associated proteins, herein dubbed the IST superfamily. The IST superfamily is defined structurally by its distorted four-helix bundle and a pair of disulfide-bonded CXXC motifs. A structure-based search of the AlphaFold human proteome identified more protein members to this superfamily; remarkably, many of these proteins are linked to gamete fusion. The SPACA6 structure and its connection to other IST-superfamily members provide a missing link in our knowledge of mammalian gamete fusion.

PubMed: 36115925
DOI: 10.1038/s42003-022-03883-y

実験手法

X-RAY DIFFRACTION (2.25 Å)