caa a22 4500 477136230 CHVBK 20180405111718.0 cr unu---uuuuu 170330e19970101xx s 000 0 eng 10.1023/A:1018611316059 doi (NATIONALLICENCE)springer-10.1023/A:1018611316059 1H and 15N NMR resonance assignments and secondary structure of titin type I domains [Elektronische Daten] [Claudia Muhle-Goll, Michael Nilges, Annalisa Pastore] Titin/connectin is a giant muscle protein with a highly modular architecture consisting ofmultiple repeats of two sequence motifs, named type I and type II. Type I modules have beensuggested to be intracellular members of the fibronectin type III (Fn3) domain family. Alongthe titin sequence they are exclusively present in the region of the molecule located in thesarcomere A-band. This region has been shown to interact with myosin and C-protein. Oneof the most noticeable features of type I modules is that they are particularly rich insemiconserved prolines, since these residues account for about 8% of their sequence. We havedetermined the secondary structure of a representative type I domain (A71) by 15N and 1HNMR. We show that the type I domains of titin have the Fn3 fold as proposed, consisting ofa three- and a four-stranded β-sheet. When the two sheets are placed on top of each other toform the β-sandwich characteristic of the Fn3 fold, 8 out of 10 prolines are found on the sameside of the molecule and form an exposed hydrophobic patch. This suggests that thesemiconserved prolines might be relevant for the function of type I modules, providing asurface for binding to other A-band proteins. The secondary structure of A71 was structurallyaligned to other extracellular Fn3 modules of known 3D structure. The alignment shows thattitin type I modules have closest similarity to the first Fn3 domain of Drosophila neuroglian. Kluwer Academic Publishers, 1997 Connectin nationallicence Modular proteins nationallicence Muscle nationallicence Fibronectin nationallicence Muhle-Goll Claudia European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut Nilges Michael European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut Pastore Annalisa European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut Journal of Biomolecular NMR Kluwer Academic Publishers 9/1(1997-01-01), 2-10 0925-2738 9:1<2 1997 9 10858 https://doi.org/10.1023/A:1018611316059 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018611316059 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Muhle-Goll Claudia European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut NATIONALLICENCE 700 1- Nilges Michael European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut NATIONALLICENCE 700 1- Pastore Annalisa European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117, Heidelberg, Germany aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Kluwer Academic Publishers 9/1(1997-01-01), 2-10 0925-2738 9:1<2 1997 9 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer