LRR, Leucine rich repeats

LRR leucine-rich repeat NARP/MILS neuropathy, ataxia, retinitis pigmentosa/maternally... 

F. 7 PARKS LRRK2 structure tuid mutations. ANK, ankyrin repeat region LRR, leucine-rich repeat domain ROC, Ras of complex COR, C-terminal of Ras (GTPase) (Tan et al., 2(X)7). Scale is approximate... 

Sequence motifs [33330 ANK (ANKyrin-like) repeats AAA (ATPases associated with a variety of cellular activities) domain or CAD (conserved ATPase domain) with Walker A and B motifs KEKE (motif rich in alternating lysine (K) and glutamate (E) residues) cys box of UBPs (ubiquitin-processing enzymes) nun- LRR (leucine-rich repeat)-like motif [ZD MPN (found in Mprland Padl in the N terminus) motif ISSSSSSS PCI (for proteasome, COP9andinitiation factor 3) motif H UCH (ubiquitin C-terminal hydrolases) block. 

Figure 18.3 The mammalian lAP family. The distinct domains are shown for each lAP. (BIR—baculovirus lAP repeat CARD-caspase activation recruitment domain RING—really interesting new gene zinc finger LRR—leucine rich repeat NOD-nucleotide-binding oligomerization domain).

Abbreviations TF = transcription factor — =has role in LRR = leucine-rich-repeat GPCR = G-protein-coupled receptor NCAM = neural adhesion molecule ... 

LRR leucine-rich repeat (amino acid/protein)... 

At least 12 ditferent TLRs have so far been identified in mammals (Uematsu and Akria 2007). TLRs are type I transmembrane PRRs that possess an extracellular domain contaiiung leucine-rich repeats (LRR), a transmembrane domain, and an... 

The crystal structure of one LRR protein, the RNAse inhibitor, has revealed that leucine-rich repeats correspond to p-a structural units. This units are arranged for a parallel p-sheet with one surface exposed to solvent so that the protein acquires an unusual non-globular shape, which may be responsible for proteinbinding functions [57]. 

A third myelin inhibitory protein, OMgp, is a GPI-linked protein expressed by oligodendrocytes [18], OMgp is a relatively minor component of myelin, believed to be localized to the paranodal loops, next to the node of Ranvier. OMgp contains a leucine-rich repeat (LRR) domain and a C-terminal domain with serine/threonine repeats. Like MAG, OMgp is also found in the PNS. Like Nogo, OMgp is also expressed in adult neurons. 

The R proteins, which act as receptors for Avr, and other elicitor proteins, are usually leucine-rich-repeat proteins with a characteristic nucleotide binding site attached (NB-LRR proteins).534,537 Like other cell surface receptors they participate in signaling and utilize both ion channels and Ser/Thr protein kinases.538 The Arabidopsis genome contains 150 sequences that may represent NB-LRR receptors.530... 

Leucine-rich repeats represent binding motifs found in a wide variety of both plant and mammalian proteins (Kobe and Kajava, 2001). These are involved in a multitude of protein-protein interactions. The sequence of porcine ribonuclease inhibitor, for example, displays a leucine-rich repeat (LRR) of length 27-29 residues that occurs 15 times in tandem (Fig. 9). Likewise, the family of small leucine-rich proteoglycans that includes biglycan, decorin, epiphycan, fibromodulin, keratocan, and lumican... 

Fig. 9. The conformation adopted by a leucine-rich repeat (LRR) is that of a /9-strand followed by an o-helix. In porcine ribonuclease inhibitor, a /9-strand (residues 2-8) is connected to an o-helix (residues 14—27) by a connecting loop (residues 9-13). A horseshoe-shaped structure is formed and is exemplified in the crystal structure of ribonuclease inhibitor (PDB 1A4Y Kobe and Deisenhofer, 1993). This has an inner concave surface formed by curved /9-sheets and an outer convex surface formed by oh el ices. The leucines and other large apolar residues form the hydrophobic core of the structure.

RNA-binding activity. The other sub-domain is a leucine-rich repeat (LRR) domain. LRR does not show general RNA-binding activity, but it is required for specific binding to the CTE. Recognition of CTE... 

Figure 13.3 Domain organization of Tap. Human Tap is a 619-amino acids protein. The minimal CTE-binding domain is composed of two globular sub-domains (the ribonucleprotein or RNP domain and the leucine-rich repeat or LRR) and a flexible N-terminal region. Also shown is the localization of the C-terminal nucleocytoplasmic shuttling domain, the cargo-binding domain, and the NTF2-like domain that exhibits pi5 binding activity.

Matsushima, N., Tanaka, T., Enkhbayar, P., Mikami, T., Taga, M., Yamada, K., Kuroki, Y. Comparative sequence analysis of leucine-rich repeats (LRRs) within vertebrate toll-like receptors. BMC Genomics 8 (2007) 124. 

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