A 3.3-A cryo-EM structure of an engineered high-affinity human prothrombinase complex.

ABSTRACT:

Abstract

Thrombin is generated from prothrombin through cleavage at 2 sites by the enzyme prothrombinase, composed of factor Xa (fXa) and fVa. The affinity of fXa for fVa is low, with assembly and function dependent on phospholipid (PL) membranes. Some snakes have evolved venom versions of fXa that bind to fVa with high affinity and efficiently activate prothrombin in the absence of PL. We created a similar high-affinity, PL-independent human prothrombinase with 17 mutations to human fXa (M17). The increase in affinity enabled cryogenic electron microscopy (cryo-EM) structure determination of M17-prothrombinase to a resolution of 3.3 Å. All protein domains were well resolved in the map, except for the γ-carboxyglutamic acid domain of fXa. The main contacts involve the serine protea

SUBMITTER: Ustok FI 

PROVIDER: S-EPMC12883857 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature