21 November 1997
Vol 278, Issue 5342

About The Cover

Unlike those found in normal chloroplasts, thylakoid membranes (colored red) from mutant hcf106 (high-chlorophyll fluorescence) maize leaves are not subdivided into stacks. Instead, they frequently adopt a uniform whorled arrangement (here ~2 to 3 micrometers in diameter). The Hcf106 gene is conserved in bacterial genomes and encodes a membrane protein that mediates protein translocation independent of the SecA translocation pathway. See 1467. [Image: A. M. Settles, J. Barr, and R. Martienssen]