4034 Nucleic Acids Research, 2011, Vol. 39, No. 10 44. Koning,L.D., Corpet,A., Haber,J.E. and Almouzni,G. (2007) Histone chaperones: an escort network regulating histone trafﬁc. Nat. Struct. Mol. Biol., 14, 997–1007. 45. Ruone,S., Rhoades,A.R. and Formosa,T. (2003) Multiple Nhp6 molecules are required to recruit Spt16-Pob3 to form yFACT complexes and to reorganize nucleosomes. J. Biol. Chem., 278, 45288–45295. 46. Birch,J.L., Tan,B.C.M., Panov,K.I., Panova,T.B., Andersen,J.S., Hughes,T.A.O., Russell,J., Lee,S.C. and Zomerdijk,J.C.B.M. (2009) FACT facilitates chromatin transcription by RNA polymerases I and III. EMBO J., 28, 854–865. 47. Morse,R.H., Roth,S.Y. and Simpson,R.T. (1992) A transcriptionally active tRNA gene interferes with nucleosome positioning in vivo. Mol. Cell. Biol., 12, 4015–4025. 48. Pusarla,R.H. and Bhargava,P. (2005) Histones in functional diversiﬁcation. Core histone variants. FEBS J., 272, 5149–5168. 49. Santisteban,M.S., Kalashnikova,T. and Smith,M.M. (2000) Histone H2A.Z regulates transcription and is partially redundant with nucleosome remodeling complexes. Cell, 103, 411–422. 50. Zlatanova,J. and Thakar,A. (2008) H2A.Z: view from the top. Structure, 16, 166–179. 51. DeRisi,J.L., Iyer,V.R. and Brown,P.O. (1997) Exploring the metabolic and genetic control of gene expression on a genomic scale. Science, 278, 680–686. 52. Uffenbeck,S.R. and Krebs,J.E. (2006) The role of chromatin structure in regulating stress-induced transcription in Saccharomyces cerevisiae. Biochem. Cell Biol., 84, 477–489. 53. Kumar,S.V. and Wigge,P.A. (2009) H2A.Z-containing nucleosomes mediate the thermosensory response in Arabidopsis. Cell, 140, 136–147. 54. Lopez,S., Livingstone-Zatchej,M., Jourdain,S., Thoma,F., Sentenac,A. and Marsolier,M.C. (2001) High-mobility-group proteins NHP6A and NHP6B participate in activation of the RNA polymerase III SNR6 gene. Mol. Cell. Biol., 21, 3096–3104. 55. Kruppa,M., Moir,R.D., Kolodrubetz,D. and Willis,I.M. (2001) Nhp6, an HMG1 protein, functions in SNR6 transcription by RNA polymerase III in S. cerevisiae. Mol. Cell, 7, 309–318. 56. Hartley,P.D. and Madhani,H.D. (2009) Mechanisms that specify promoter nucleosome location and identity. Cell, 137, 445–458. 57. Parnell,T.J., Huff,J.T. and Cairns,B.R. (2007) RSC regulates nucleosome positioning at Pol II genes and density at Pol III genes. EMBO J., 27, 100–110.