Abstract

Many macromolecular folding reactions, such as the Mg2+-dependent folding of the Tetrahymena thermophila group I intron, occur on timescales ranging from milliseconds to minutes. Kinetic progress curves describing the millisecond folding of P4-P6 and other domains within the L-21 ribozyme have been obtained using a new ?OH ?footprinting? technique, stopped-flow synchrotron x-ray ?footprinting?. The folding of P4-P6 is a highly concerted reaction; the regions of ?OH protection within the interior of the folded domain appear at rates of ? 1.0 sec-1. ?OH protections within the P5c sub-domain appear at rates of ~ 2.0 sec-1, suggesting that folding of this subdomain is the initial step in the folding pathway. The rates of ?OH protection of the ?triple helix? junction between P4-P6 and the P3-P7 domain and those protections in P4-P6 ascribed to interaction with the P9 domain at rates of ~ 0.3 sec-1. These results suggest that these tertiary interactions guide the folding of the catalytic core against an extensively folded P4-P6 domain. To further dissect the folding mechanism of the Tetrahymena ribozyme, which we have solved in detail for a single set of conditions, the magnesium and temperature dependence of the folding mechanism will be explored in order to correlate the changes in energetics and structure that occur along the folding pathway.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001633-19
Application #
6491433
Study Section
Project Start
2001-09-01
Project End
2002-08-31
Budget Start
Budget End
Support Year
19
Fiscal Year
2001
Total Cost
Indirect Cost

  Institution

Name
Albert Einstein College of Medicine
Department
Type
DUNS #
009095365
City
Bronx
State
NY
Country
United States
Zip Code
10461

  Publications

Vongsvivut, Jitraporn; Fernandez, Jason; Ekgasit, Sanong et al. (2004) Characterization of supported cylinder-planar germanium waveguide sensors with synchrotron infrared radiation. Appl Spectrosc 58:143-51
Masip, Lluis; Pan, Jonathan L; Haldar, Suranjana et al. (2004) An engineered pathway for the formation of protein disulfide bonds. Science 303:1185-9
Huang, Raymond Y; Miller, Lisa M; Carlson, Cathy S et al. (2003) In situ chemistry of osteoporosis revealed by synchrotron infrared microspectroscopy. Bone 33:514-21
Rashidzadeh, Hassan; Khrapunov, Sergei; Chance, Mark R et al. (2003) Solution structure and interdomain interactions of the Saccharomyces cerevisiae ""TATA binding protein"" (TBP) probed by radiolytic protein footprinting. Biochemistry 42:3655-65
Uchida, Takeshi; Takamoto, Keiji; He, Qin et al. (2003) Multiple monovalent ion-dependent pathways for the folding of the L-21 Tetrahymena thermophila ribozyme. J Mol Biol 328:463-78
Taylor, Colleen M; Watton, Stephen P; Bryngelson, Peter A et al. (2003) Inner-sphere complexation of cobalt(II) 2,9-dimethyl-1,10-phenanthroline ([Co(neo)]2+) with commercial and sol-gel derived silica gel surfaces. Inorg Chem 42:312-20
Tang, Qun; Carrington, Paul E; Horng, Yih-Chern et al. (2002) X-ray absorption and resonance Raman studies of methyl-coenzyme M reductase indicating that ligand exchange and macrocycle reduction accompany reductive activation. J Am Chem Soc 124:13242-56
Guan, Jing-Qu; Vorobiev, Sergeui; Almo, Steven C et al. (2002) Mapping the G-actin binding surface of cofilin using synchrotron protein footprinting. Biochemistry 41:5765-75
Chance, Mark R; Bresnick, Anne R; Burley, Stephen K et al. (2002) Structural genomics: a pipeline for providing structures for the biologist. Protein Sci 11:723-38
Maleknia, Simin D; Kiselar, Janna G; Downard, Kevin M (2002) Hydroxyl radical probe of the surface of lysozyme by synchrotron radiolysis and mass spectrometry. Rapid Commun Mass Spectrom 16:53-61

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