Domains protein domain characteristics

These interactions involve adhesion proteins called selectins, which are found both on the rolling leukocytes and on the endothelial cells of the vascular walls. Selectins have a characteristic domain structure, consisting of an N-terminal extracellular lectin domain, a single epidermal growth factor (EGR) domain, a series of two to nine short consensus repeat (SCR) domains, a single transmembrane segment, and a short cytoplasmic domain. Lectin domains, first characterized in plants, bind carbohydrates... 

Adaptor Proteins. Figure 1 Adaptor protein domains. A scheme of the domain structures of some well-characterized adaptor proteins is shown. Descriptions of domain characteristics are in main text except C2, binds to phospholipids GTPase activating protein (GAP) domain, inactivates small GTPases such as Ras Hect domain, enzymatic domain of ubiquitin ligases and GUK domain, guanylate kinase domain. For clarity, not all domains contained within these proteins are shown. 

Blaak, H., Schnellmann, J., Walter, S., Henrissat, B. and Schrempf, H. (1993) Characteristics of an exochitinase from Streptomyces olivaceoviridis, its corresponding gene, putative protein domains and relationship to other chitinases. European Journal of Biochemistry 214, 659-669. 

The structural element of PARK that interacts specifically with the Py-complex is localized in the C-terminal third of the PARK seqimce (Inglese et al., 1994). It possesses the characteristics of an independently folding protein domain and is ranked with the pleckstrin homology domains (PH domains). The PH domains are protein modules (see Chapter 8), foimd in many proteins, that by binding of inositol lipids (see Chapter 6) mediate protein-membrane interactions. 

Another area in which Zn(II) complexes play an important role concerns the recognition of CysaHisa zinc-finger protein domains, which exhibit a characteristic tetrahedral structure as shown in Figure 7. More than 4000 such domains are present in over 700 proteins . 

DNA sequence determination and analysis, gene MHCK possesses all of the domains characteristic of members ofthe protein kinase C family [16]) [16] <9> (DNA sequence determination and analysis [19]) [19]... 

The fundamental structure of immunoglobulins was first established by Gerald Edelman and Rodney Porter. Each chain is made up of identifiable domains some are constant in sequence and structure from one IgG to the next, others are variable. The constant domains have a characteristic structure known as the immunoglobulin fold, a well-conserved structural motif in the all /3 class of proteins (Chapter 4). There are three of these constant domains in each heavy chain and one in each light chain. The heavy and light chains also have one variable domain each, in which most of the variability in amino acid residue sequence is found. The variable domains associate to create the antigen-binding site (Fig. 5-24). 

Another superfamily is formed by bacterial di-heme CCP (with over 110 entries in PeroxiBase) that are periplasmic enzymes providing protection from oxidative stress. These homodimeric enzymes have a conserved tertiary structure containing two type-c hemes covalently attached to two predominantly a-helical domains via a characteristic binding motif. One heme acts as a low redox-potential center where H2O2 is reduced, and the other as a high redox-potential center that feeds electrons to the peroxidatic site from soluble electron-shuttle proteins such as cytochrome c [24]. In the crystal structure of the Geobacter sulfurreducens enzyme shown in Fig. 3.1g, the first heme appears as a bis-histidinyl-coordinated form (and... 

Interestingly, plant AGPs have been also impbcated in cellular processes that are identical to those described above for phytocyanins (Noth-nagel, 1997). As we have already mentioned, most phytocyanins in their mature form are predicted to be composed of a BCB domain and a domain with sequence characteristics reminiscent of those of described for AGPs. Thus, phytocyanins are interesting examples of the recently developed Rosetta stone sequence concept, which postulates that when two different proteins also occur in parallel as a fused, larger composite protein, it is an indication that they are functionally related and may even physically interact (Eisenberg et al., 2000 Marcotte, 2000). 

Fig. 3.9 (a) A ribbon presentation of the structure of the human tyrosine-specific phosphatase IB, (PTPIB). It is a single-domain protein with a seven-stranded, mixed b-sheet, flanked by a-helices. The catalytic site is in the central region, in a shallow cleft. The phosphate-recognition site is characteristic for PTPs. It is formed by a loop containing the C(X5>R motif, which contains the catalytically essential cysteine and arginine residues. (Reproduced with permission of the authors, D.Barford, A. J. Flint, and N. K.Tonks, and Science from ref. 78.)... 

Figure 3. Hierarchical domain clustering of MASC proteins. Interpro domains in MASC proteins occurring more than once in the MASC dataset were clustered. Discrete clusters (grey boxes) were annotated with the protein class of which the majority proteins belonged to. Clusters are formed from co-occurrence of two or more domains characteristic of a protein class...

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