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

Ex 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.

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

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:
Hurry! Time to "steal vegetables" Don't be afraid! We are not encouraging the stealing behavior, but to tell you maybe the most popular topic from white-collars' mouth in cities. Together with "How many vegetables do you steal today," "it's harvest time for your ripe peach," "I bought you a new car today." Are there so many people in the city really have their own farms, or are they really so rich to buy someone else cars casually? The answer is obviously negative. They just play some games on Social Network Sites (SNS) like kaixin001.com. Can you imagine that more than millions of people in Chinese mainland will spend lots of time on SNS to play game and talk to friends, especially white-collars who work in the cities? Take kaixin001.com as an example, the current member of it has already hit 38 million. However, the great number of people who would like to use such SNS indicates another social problem. That is lots of people choose to escape from the reality. And SNS just offer them a Virtual space to forget the reality. Kinds of games and various of friends do give netizens lots of fun. Though indulging, dreaming, chatting and playing , it seems like people could really escape from all the upsets in reality. But virtual world is not real and no one can live in it forever, and reality is not that simple like noodling around on the internet. Since this kind of social phenomenon is so popular on the internet, people start thinking to remove it in the reality.After playing the "happy farm" game on kaixin001.com, would you like to put yourself among the real corps while smelling the fragrance of the countryside? Recently, a farm land service called "happy farm in reality" was opened in the suburbs of Shanghai where white-collar workers from around that region can experience the real farmer's life by themselves

Ex Output:
Which group are the majority playing the "Happy Farm" game?