Fig. 7: Summary and model of snR107 functions.

a Table summarizing the requirements for snR107 cis-acting motifs and Cgr1 in rRNA 2’-O-Me, 60S subunit biogenesis and the regulations of Mmi1 and Mei2. Green, orange and red boxes refer to functional, partially defective and abolished activities, respectively. The gray box indicates undetermined. b Model depicting the roles of snR107 in rRNA 2’-O-Me and the control of Mmi1 and Mei2 activities. Through its ASE1, snR107 guides 25S rRNA G2483 2’-O-Me by Fib1 (left). It further contributes to pre-rRNA processing and 60S subunit biogenesis in a Gm2483-independent manner (not shown). snr107 also mediates the Mmi1-Mei2 mutual control in vegetative cells and restricts meiotic gene expression during sexual differentiation in an ASE2-dependent manner (right). The k-loop motif is critical for both regulations by promoting the binding of Mmi1, Mei2, and Fib1. Other snoRNP components (Nop56, Nop58, Snu13) are represented as gray circles.