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

Input: Consider Input: Selenocysteine, a selenium-containing analog of cysteine, is found in the prokaryotic and eukaryotic kingdoms in active sites of enzymes involved in oxidation-reduction reactions. Its biosynthesis and cotranslational insertion into selenoproteins is performed by an outstanding mechanism, implying the participation of several gene products. The tRNA(Sec) is one of these. In eukaryotes, its transcription mode by RNA polymerase III differs from that of classical tRNA genes, both at the level of the promoter elements and transcription factors involved. In addition, enhanced transcription is afforded by a newly characterized zinc finger activator. Not only transcription of the gene, but also the tRNA(Sec) itself is atypical since its 2D and 3D structures exhibit features which set it apart from classical tRNAs. Decoding of eukaryotic selenocysteine UGA codons requires a stem-loop structure in the 3'UTR of mRNAs, the selenocysteine insertion sequence (SECIS) element. Structure probing and sequence comparisons led us to propose a 2D structure model for the SECIS element, containing a novel RNA motif composed of four consecutive non-Watson-Crick base-pairs. A 3D model, rationalizing the accessibility data, was elaborated by computer modeling. It yields indicative or suggestive evidence for the role that could play some conserved residues and/or structural features in SECIS function. These might act as signals for interaction with SBP, the SECIS binding protein that we have characterized.

Output: What is the name of the stem loop present in the 3' end of genes encoding for selenoproteins?

Input: Consider Input: Heroes of Gaia (Chinese: ; pinyin: Yingxiong Zhi Cheng), known in the separate European version as Castle of Heroes, is a massively multiplayer online fantasy browser-based strategy game developed by the Chinese developer Snail Games and published in the United States by its U.S. publishing division, Snail Games USA.

Output: Who worked on Heroes of Gaia?

Input: Consider Input: The Flute sonata in E minor (HWV 379) was composed (circa 1727-28) by George Frideric Handel for flute and keyboard (harpsichord).
Output: What is the musical instrument Flute sonata in E minor (HWV 379) was intended for?