دورية أكاديمية
Biochemical characterization of Mycobacterium tuberculosis LexA and structural studies of its C-terminal segment.
| العنوان: | Biochemical characterization of Mycobacterium tuberculosis LexA and structural studies of its C-terminal segment. |
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| المؤلفون: | Chandran AV; Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India., Srikalaivani R; Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India., Paul A; Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India., Vijayan M; Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India. |
| المصدر: | Acta crystallographica. Section D, Structural biology [Acta Crystallogr D Struct Biol] 2019 Jan 01; Vol. 75 (Pt 1), pp. 41-55. Date of Electronic Publication: 2019 Jan 07. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: John Wiley & Sons Country of Publication: United States NLM ID: 101676043 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 2059-7983 (Electronic) Linking ISSN: 20597983 NLM ISO Abbreviation: Acta Crystallogr D Struct Biol Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: <2018-> : Medford, MA : John Wiley & Sons Original Publication: [Malden, MA] : John Wiley & Sons, [2016]- |
| مواضيع طبية MeSH: | Bacterial Proteins/*chemistry , Mycobacterium tuberculosis/*chemistry , Serine Endopeptidases/*chemistry, Bacterial Proteins/genetics ; Mutant Proteins ; Protein Domains ; Protein Multimerization ; SOS Response, Genetics ; Serine Endopeptidases/genetics |
| مستخلص: | LexA is a protein that is involved in the SOS response. The protein from Mycobacterium tuberculosis and its mutants have been biochemically characterized and the structures of their catalytic segments have been determined. The protein is made up of an N-terminal segment, which includes the DNA-binding domain, and a C-terminal segment encompassing much of the catalytic domain. The two segments are defined by a cleavage site. Full-length LexA, the two segments, two point mutants involving changes in the active-site residues (S160A and K197A) and another mutant involving a change at the cleavage site (G126D) were cloned and purified. The wild-type protein autocleaves at basic pH, while the mutants do not. The wild-type and the mutant proteins dimerize and bind DNA with equal facility. The C-terminal segment also dimerizes, and it also shows a tendency to form tetramers. The C-terminal segment readily crystallized. The crystals obtained from attempts involving the full-length protein and its mutants contained only the C-terminal segment including the catalytic core and a few residues preceding it, in a dimeric or tetrameric form, indicating protein cleavage during the long period involved in crystal formation. Modes of tetramerization of the full-length protein similar to those observed for the catalytic core are feasible. A complex of M. tuberculosis LexA and the cognate SOS box could be modeled in which the mutual orientation of the two N-terminal domains differs from that in the Escherichia coli LexA-DNA complex. These results represent the first thorough characterization of M. tuberculosis LexA and provide definitive information on its structure and assembly. They also provide leads for further exploration of this important protein. |
| فهرسة مساهمة: | Keywords: DNA binding; LexA; Mycobacterium tuberculosis; SOS response; autocleavage; oligomerization |
| المشرفين على المادة: | 0 (Bacterial Proteins) 0 (LexA protein, Bacteria) 0 (Mutant Proteins) EC 3.4.21.- (Serine Endopeptidases) |
| تواريخ الأحداث: | Date Created: 20190116 Date Completed: 20190520 Latest Revision: 20191210 |
| رمز التحديث: | 20221213 |
| DOI: | 10.1107/S2059798318016066 |
| PMID: | 30644844 |
| قاعدة البيانات: | MEDLINE |
Full Text Finder | تدمد: | 2059-7983 |
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| DOI: | 10.1107/S2059798318016066 |