Browsing by Author "Bogans, Janis"

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    Structural characterization of CspZ, a complement regulator factor H and FHL-1 binding protein from Borrelia burgdorferi
    (2014-06) Brangulis, Kalvis; Petrovskis, Ivars; Kazaks, Andris; Bogans, Janis; Otikovs, Martins; Jaudzems, Kristaps; Ranka, Renate; Tars, Kaspars; Rīga Stradiņš University
    Borrelia burgdorferi is the causative agent of Lyme disease and is found in two different types of hosts in nature - Ixodes ticks and various mammalian organisms. To initiate disease and survive in mammalian host organisms, B. burgdorferi must be able to transfer to a new host, proliferate, attach to different tissue and resist the immune response. To resist the host's immune response, B. burgdorferi produces at least five different outer surface proteins that can bind complement regulator factor H (CFH) and/or factor H-like protein 1 (CFHL-1). The crystal structures of two uniquely folded complement binding proteins, which belong to two distinct gene families and are not found in other bacteria, have been previously described. The crystal structure of the CFH and CFHL-1 binding protein CspZ (also known as BbCRASP-2 or BBH06) from B. burgdorferi, which belongs to a third gene family, is reported in this study. The structure reveals that the overall fold is different from the known structures of the other complement binding proteins in B. burgdorferi or other bacteria; this structure does not resemble the fold of any known protein deposited in the Protein Data Bank. The N-terminal part of the CspZ protein forms a four-helix bundle and has features similar to the FAT domain (focal adhesion targeting domain) and a related domain found in the vinculin/α-catenin family. By combining our findings from the crystal structure of CspZ with previous mutagenesis studies, we have identified a likely binding surface on CspZ for CFH and CFHL-1.
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    Structural studies of chromosomally encoded outer surface lipoprotein BB0158 from Borrelia burgdorferi sensu stricto
    (2024-01) Brangulis, Kalvis; Akopjana, Inara; Bogans, Janis; Kazaks, Andris; Tars, Kaspars
    Lyme disease, or also known as Lyme borreliosis, is caused by the spirochetes belonging to the Borrelia burgdorferi sensu lato complex, which can enter the human body following the bite of an infected tick. Many membrane lipid-bound proteins, also known as lipoproteins, are located on the surface of B. burgdorferi sensu lato and play a crucial role in the spirochete to interact with its environment, whether in ticks or mammals. Since the spirochete needs to perform various tasks, such as resisting the host's immune system or spreading throughout the organism, it is not surprising that numerous surface proteins have been found to be essential for B. burgdorferi sensu lato complex bacteria in causing Lyme disease. In this study, we have determined (at 2.4 Å resolution) and characterized the 3D structure of BB0158, one of the few chromosomally encoded outer surface proteins from B. burgdorferi sensu stricto. BB0158 belongs to the paralogous gene family 44 (PFam44), consisting of four other members (BB0159, BBA04, BBE09 and BBK52). The characterization of BB0158, which appears to form a domain-swapped dimer, in conjunction with the characterization of the corresponding PFam44 members, certainly contribute to our understanding of B. burgdorferi sensu stricto proteins.