Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Ex Input:
The SET domain contains the catalytic center of lysine methyltransferases that target the N-terminal tails of histones and regulate chromatin function. Here we report the structure of the SET7/9 protein in the absence and presence of its cofactor product, S-adenosyl-L-homocysteine (AdoHcy). A knot within the SET domain helps form the methyltransferase active site, where AdoHcy binds and lysine methylation is likely to occur. A structure-guided comparison of sequences within the SET protein family suggests that the knot substructure and active site environment are conserved features of the SET domain.

Ex Output:
What is the characteristic domain of histone methyltransferases?


Ex Input:
Yana De Leeuw (born 6 September 1990) is a Belgian female former volleyball player, playing as a setter.

Ex Output:
Which sex or gender can Yana De Leeuw be described as?


Ex Input:
The Flute sonata in E minor (HWV 379) was composed (circa 1727-28) by George Frideric Handel for flute and keyboard (harpsichord).

Ex Output:

What is the musical instrument Flute sonata in E minor (HWV 379) was intended for?