Comparative Geometrical Analysis of Leucine-Rich Repeat Structures in the Nod-Like and Toll-Like Receptors in Vertebrate Innate Immunity

Biomolecules

Norio Matsushima³  Hiroki Miyashita³  Purevjav Enkhbayar²  Robert H. Kretsinger¹ 

[1] Department of Biology, University of Virginia, Charlottesville, VA 22904, USA; E-Mail:;Department of Information and Computer Science, School of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar 210646/377, Mongolia; E-Mail:;The Institute of Tandem Repeats, Sapporo 060-8556, Japan; E-Mail:

关键词: TLRs;    NLRs;    receptor;    RP105;    CD14;    helix;    dimer;   

DOI  :  10.3390/biom5031955

来源: mdpi

【 摘 要 】

The NOD-like receptors (NLRs) and Toll-like receptors (TLRs) are pattern recognition receptors that are involved in the innate, pathogen pattern recognition system. The TLR and NLR receptors contain leucine-rich repeats (LRRs) that are responsible for ligand interactions. In LRRs short β-strands stack parallel and then the LRRs form a super helical arrangement of repeating structural units (called a coil of solenoids). The structures of the LRR domains of NLRC4, NLRP1, and NLRX1 in NLRs and of TLR1-5, TLR6, TLR8, TLR9 in TLRs have been determined. Here we report nine geometrical parameters that characterize the LRR domains; these include four helical parameters from HELFIT analysis. These nine parameters characterize well the LRR structures in NLRs and TLRs; the LRRs of NLR adopts a right-handed helix. In contrast, the TLR LRRs adopt either a left-handed helix or are nearly flat; RP105 and CD14 also adopt a left-handed helix. This geometrical analysis subdivides TLRs into four groups consisting of TLR3/TLR8/TLR9, TLR1/TLR2/TRR6, TLR4, and TLR5; these correspond to the phylogenetic tree based on amino acid sequences. In the TLRs an ascending lateral surface that consists of loops connecting the β-strand at the C-terminal side is involved in protein, protein/ligand interactions, but not the descending lateral surface on the opposite side.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.