An extended RNA binding surface through arrayed S1 and KH domains in transcription factor NusA.
The crystal structure of Thermotoga maritima NusA, a transcription factor involved in pausing, termination, and antitermination processes, reveals a four-domain, rod-shaped molecule. An N-terminal alpha/beta portion, a five-stranded beta-barrel (S1 domain), and two K-homology (KH) modules create a continuous spine of positive electrostatic potential, suitable for nonspecific mRNA attraction. Homology models suggest how, in addition, specific mRNA regulatory sequences can be recognized by the S1 and KH motifs. An arrangement of multiple S1 and KH domains mediated by highly conserved residues is seen, creating an extended RNA binding surface, a paradigm for other proteins with similar domain arrays. Structural and mutational analyses indicate that the motifs cooperate, modulating strength and specificity of RNA binding.
Worbs
M
M
Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, D-82152, Martinsried, Germany.
Bourenkov
G P
GP
Bartunik
H D
HD
Huber
R
R
Wahl
M C
MC
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D003461:Crystallography; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010445:Peptide Elongation Factors; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020124:Thermotoga maritima; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology; D035602:Transcriptional Elongation Factors
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010445:Peptide Elongation Factors; D012333:RNA, Messenger; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C068727:nusA protein, E coli; D012321:DNA-Directed RNA Polymerases