Defining the conformation of human mincle that interacts with mycobacterial trehalose dimycolate.

Trehalose dimycolate, an unusual glycolipid in the outer membrane of Mycobacterium tuberculosis, stimulates macrophages by binding to the macrophage receptor mincle. This stimulation plays an important role both in infection by mycobacteria and in the use of derivatives of mycobacteria as adjuvants to enhance the immune response. The mechanism of trehalose dimycolate binding to the C-type carbohydrate-recognition domain in human mincle has been investigated using a series of synthetic analogs of trehalose dimycolate and site-directed mutagenesis of the human protein.

A winged helix domain in human MUS81 binds DNA and modulates the endonuclease activity of MUS81 complexes.

The MUS81-EME1 endonuclease maintains metazoan genomic integrity by cleaving branched DNA structures that arise during the resolution of recombination intermediates. In humans, MUS81 also forms a poorly characterized complex with EME2. Here, we identify and determine the structure of a winged helix (WH) domain from human MUS81, which binds DNA.

Fluorescence-based incision assay for human XPF-ERCC1 activity identifies important elements of DNA junction recognition.

The structure-specific endonuclease activity of the human XPF-ERCC1 complex is essential for a number of DNA processing mechanisms that help to maintain genomic integrity. XPF-ERCC1 cleaves DNA structures such as stem-loops, bubbles or flaps in one strand of a duplex where there is at least one downstream single strand. Here, we define the minimal substrate requirements for cleavage of stem-loop substrates allowing us to develop a real-time fluorescence-based assay to measure endonuclease activity.

Tes, a specific Mena interacting partner, breaks the rules for EVH1 binding.

The intracellular targeting of Ena/VASP family members is achieved via the interaction of their EVH1 domain with FPPPP sequence motifs found in a variety of cytoskeletal proteins, including lamellipodin, vinculin, and zyxin. Here we show that the LIM3 domain of Tes, which lacks the FPPPP motif, binds to the EVH1 domain of Mena, but not to those of VASP or Evl. The structure of the LIM3:EVH1 complex reveals that Tes occludes the FPPPP-binding site and competes with FPPPP-containing proteins for EVH1 binding.

Phylogenetic analysis of the vertebrate galectin family.

Galectins form a family of structurally related carbohydrate binding proteins (lectins) that have been identified in a large variety of metazoan phyla. They are involved in many biological processes such as morphogenesis, control of cell death, immunological response, and cancer. To elucidate the evolutionary history of galectins and galectin-like proteins in chordates, we have exploited three independent lines of evidence: (i) location of galectin encoding genes (LGALS) in the human genome; (ii) exon-intron organization of galectin encoding genes; and (iii) sequence comparison of carbohydrate recognition domains (CRDs) of chordate galectins.

Molecular characterization of the rat Kupffer cell glycoprotein receptor.

The Kupffer cell receptor for glycoproteins has been reported to have a role in clearance of galactose- and fucose-terminated glycoproteins from circulation. Although the gene and a cDNA encoding the receptor have been described, there has been little study of the receptor protein. To address some questions about possible ligands and functions for this receptor, fragments representing portions of the extracellular domain have been expressed and characterized.

Genomic analysis of C-type lectins.

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell-cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible.