Rabbit Anti-Human FBL Polyclonal Antibody Knockout Validated

A gene called fbl, encoding a Staphylococcus lugdunensis fibrinogen-binding protein, was identified by phage display. The encoded protein, Fbl, is a member of the Sdr-family, a group of staphylococcal cell surface proteins containing a characteristic serine-aspartate repeat region. The fibrinogen-binding domain was mapped to 313 amino acids, and shows, 62% identity to the corresponding region in clumping factor (ClfA) from Staphylococcus aureus. Anti-serum against ClfA cross-reacted with Fbl, and blocked S. lugdunensis adherence to fibrinogen. Twelve clinical isolates of S. lugdunensis analysed by Southern blot all had an fbl-like gene. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

Fibrillarin (FBL) is an essential nucleolar protein that participates in pre-rRNA methylation and processing. The methyltransferase domain of FBL is an example of an extremely well-conserved protein domain in which the amino acid sequence was not substantially modified during the evolution from Archaea to Eukaryota. An additional N-terminal glycine-arginine-rich (GAR) domain is present in the FBL of eukaryotes. Here, we demonstrate that the GAR domain is involved in FBL functioning and integrates the functions of the nuclear localization signal and the nucleolar localization signal (NoLS). The methylation of the arginine residues in the GAR domain is necessary for nuclear import but decreases the efficiency of nucleolar retention via the NoLS. The presented data indicate that the GAR domain can be considered an evolutionary innovation that integrates several functional activities and thereby adapts FBL to the highly compartmentalized content of the eukaryotic cell.