R loops modulate binding of chromatin remodelers at promoters of coding and non-coding genes to control transcription and cellular differentiation. Cover image by © Stocktrek Images/Thinkstock.(pp 999–1007)

In this issue, we present a Focus on Telomeres (http://www.nature.com/nsmb/focus/telomeres2015) with Reviews, Perspectives and a Commentary that discuss the maintenance and protection of chromosome ends, the regulation of telomerase activity, and telomere dysfunction in human disease. Cover design by Erin Dewalt, based on image provided by Tony Cesare, showing telomeres of human metaphase chromosomes visualized by CO-FISH. (pp 839–882)

Stabilized capsids of foot-andmouth disease virus, engineered by strengthening protein-protein interfaces, generate improved antibody responses in calves and guinea pigs.Cover image by © Tetiana Vitsenko/Alamy Stock Photo (pp 788–794)

The dimeric transmembrane protein PsbS plays a key role in plant photoprotection. Crystallographic and biochemical analyses provide insight into PsbS pH-dependent activation. Cover image by © AlexPro9500/iStock/Thinkstock (pp 729–735, News and Views (p 650)

The flexibility of filamentous plant viruses has been a challenge to their structural characterization.A cryo-EM structure of the bamboo mosaic potexvirus now elucidates the molecular basis of this flexibility. Cover image by © moodboard/Thinkstock (pp 642–644)

The integral membrane protein stearoyl-CoA desaturase-1 introduces a double bond into stearoyl-CoA during the biosynthesis of unsaturated fatty acids. Crystallographic analysis of human SCD-1 provides atomic details of the interaction with its substrate. Cover design by Erin Dewalt. (pp 581–585)

Competition of CRY1 with coactivators for binding to the BMAL1 transcriptional activation domain regulates circadian cycling.Cover image by © Ryan McVay /Photodisc / Thinkstock (pp 476–484, News and Views p 435)

Crystal structures of rhodopsin KR2,a light-driven sodium pump, reveal the translocation pathway of sodium ions and shed light on the molecular mechanism of ion pumping. Cover image by © Andres Rodriguez / Alamy (pp 390–395, News and Views p 351)

Jopling, Proudfoot and colleagues show that long noncoding RNA transcripts hosting microRNAs use Microprocessor to terminate transcription, thus revealing a novel RNase III-mediated transcriptional termination pathway. Cover image by © Thinkstock Images. pp 319–327, News and Views p 279

Crystallographic studies by Wang and colleagues reveal the structure of the bacterial vitamin C transporter UlaA and elucidate ascorbate binding and transport across the cell membrane. Cover image by © Iaroslav Danylchenko / Alamy. pp 238–241

Structural studies by Lührmann, Pena and colleagues show how the RNA helicase Aquarius is recruited to the spliceosome, and reveal that Aquarius is positioned by a novel spliceosomal building block. The cover features the Aquarius constellation; cover design by Erin Dewalt based on photograph by Athos Boncompagni/iStock/Thinkstock. pp 138–144

This Focus on noncoding RNAs presents specially commissioned Commentaries, Reviews and a Perspective that highlight the remarkable functional diversity of these molecules and discuss recent advances and challenges in noncoding RNA biology. Cover design by Erin Dewalt. pp 1–36