N-domain

Figure 13.31 Space-filling diagram of Src tyrosine kinase in the same view as Figure 13.30. The SH2 domain makes only a few contacts with the rest of the molecule except for the tail region of the kinase. The SH3 domain contacts the N-domain of the kinase in addition to the linker region. There are extensive contacts between the N- and C-domains of the kinase. (Adapted from W. Xu et al., Nature 385 596-602, 1997.)...

NMR spectroscopy of purified soluble Ure2p has shown that an N-terminal tract of about 90 amino acids is unfolded (Pierce et al., 2005). This observation explains the acute sensitivity to proteolysis of the N-domains of soluble Ure2p (Baxa et al., 2003 Thual et al., 1999). Similarly, NMR analysis of soluble HET-s showed the region of amino acids 218-289 to be unfolded (Balguerie et al., 2003). 

Synthesis of Novel Ketomethylene N Domain Selective Ace Inhibitors... 

Fig. 10.2. HsIL) surface colored according to domain. (A) View along the six-fold axis, seen from the side opposite to the l-domains. (B) View along the six-fold axis, seen from the side of the l-domains. Every second subunit of the ring is colored according to domain (N-domain yellow, l-domain blue, C-domain orSSD-domain red), the other subunits are colored in green. The diagram is based on the trigonal...

M. R., and XiA, D. Crystal structure of the heterodimeric complex of the adapter, ClpS, with the N-domain of the AAA+ chaperone, ClpA. J. Biol. Chem. 2002a, 277, 46753-46762. 

Angiotensin converting enzyme (ACE) is an important enzyme for the regulation of blood pressure, ft exists in two forms the somatic form has 1277 amino acids, while the sperm cell form has 701 amino acids. The somatic form consists of two domains the carboxy-terminal (C) domain and the amino-terminal (N) domain. The sperm cell form consists of only the C domain. Studies have shown that the C domain is the dominant angiotensin converting site for controlling blood pressure and cardiovascular functions. 

The reference 13 author compared the N-domain NaTK -ATPase X-ray crystallographic structure with NMR solution structures also published in 2003... 

ATP binds, crosslinking the N and P domains. The ATP s y-phosphate and its bound Mg + ion bend the P domain. The N-domain makes contact with the A domain in a strained conformation. Part of the Ml helix is pulled up and forms a barrier to Ca + ion exchange with the cytoplasm. Calcium ions are occluded. 

MBD2a Contain MBD domain and (glycine-arginine)n domain Transcriptional repressor, a component of the Mi2/NuRD deacetylase complex MBD2b Co-localizes with heavily methylated satellite DNA in mouse cells ... 

MBD2b a truncated version of MBD2a (translation stars at a second methionine codon in MBD2a) that lacks the (GR)n domain was reported to have demethylase activity with direct removal of the methyl group expressed in somatic tissues but not ES cells... 

Binding of heme by isolated N-domain causes a change in sedimentation coefficient consistent with a more compact conformation and leads to the more avid association with the C-domain (125). Sedimentation equilibrium analysis showed that the Kd decreases from 55 pM to 0.8 pM (Fig. 5) (106). In addition, the calorimetric AH (-1-11 kcal/mol) and AS (-1-65 kcal/mol K) for the heme-N-domain-C-domain interaction and the AH (-3.6 kcal/mol) and AS (-1-8.1 kcal/mol K) derived from van t Hoff analysis of ultracentrifuge data for the interaction in the absence of heme indicate that hydrophobic interactions predominate in the presence of heme and a mix (e.g., hydrophobic and van der Waals forces) drives the interaction in the absence of heme. However, FTIR spectra (Fig. 6) indicate that little change in the secondary structure of domains or intact hemopexin occurs upon heme binding (104). 

Fig. 7. The crystal structure of the C-domain of hemopexin (PDB accession number IHXN) 128) showed a four-bladed p-propeller structure, which because of sequence similarity was also expected in the N-domain. The high degree of beta structure and limited a-helix content agrees with the earlier FTIR analysis.

The isolated C-domain recombines with heme-N-domain and alters the conformation of its partner domain (106, 125, 130), but has no intrinsic heme or porphyrin binding activity (N. Shipulina et al., unpublished). 

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