Search

Many proteins contain targeting signals within their sequences that specify their delivery to particular organelles. The peroxisomal targeting signal-1 (PTS1) is a C-terminal tripeptide that is sufficient to direct proteins into peroxisomes. The PTS1 sequence closely approximates Ser-Lys-Leu-COO-. PEX5, the receptor for PTS1, interacts with the signal via a series of tetratricopeptide repeats (TPRs) within its C-terminal half. Here we report the crystal structure of a fragment of human PEX5 that includes all seven predicted TPR motifs in complex with a pentapeptide containing a PTS1 sequence. Two clusters of three TPRs almost completely surround the peptide, while a hinge region, previously identified as TPR4, forms a distinct structure that enables the two sets of TPRs to form a single binding site. This structure reveals the molecular basis for PTS1 recognition and demonstrates a novel mode of TPR?peptide interaction. [ABSTRACT FROM AUTHOR]

Presents a thermodynamic beta-sheet propensity scale for all the commonly occurring amino acids in aqueous solution. Zinc-finger peptide as the host system with a guest position within a beta-strand; Summary of beta-sheet propensity data; Details.

Discusses research being done on the structure of zinc fingers. Reference to study by Lu, Searles and Klug, published in the journal "Nature"; Role of RNA in zinc fingers-TFIIIA protein interaction; Biological significance of zinc finger proteins; Interaction of zinc fingers with RNA; Recognition of RNA by TFIIIA proteins.

Offers a look at two new methods for probing protein-DNA interactions. Details on a novel fluorescence-based approach to monitoring protein-DNA interaction; Biochemical method for mapping, at single nucleotide resolution; How the elucidation of DNA-protein interaction will help present information on gene expression.

The author discusses the policy announced by the U.S. National Institutes of Health (NIH) which will apply to the next round of R01 grants. The author says that the application from investigators receiving more than $1 million a year in funding from the NIH are subjected to extra review. He suggests that the policy will complement peer review and help determine the best possible portfolio of NIH research.

Presents a correction to an article on molecular biology entitled 'Peroxismal targeting signal-1 recognition by the TPR domains of human PEX5,' published in the 2002 issue of 'Nature Structural Biology.'