MMSYN1 0107 ri25chen
- ID: MMSYN1_0107
- Name: nusB: transcription antitermination factor NusB
- Organism: JCVI-Syn3.0
- UniProt ID: Q6MUD0
- Description: Involved in the transcription termination process. One of the proteins essential for the formation of the RNA polymerase antitermination complex in the presence of lambda phage N protein. However, it is involved in the transcription termination process at certain sites during normal bacterial growth. Binds to the BoxA RNA motif.
The nusB (groNB) gene product of Escherichia coli plays a pivotal role in allowing bacteriophage lambda N protein to function as an antiterminator of mRNA transcription and in modulating host gene expression. Transcriptional polarity in rRNA operons of Escherichia coli nusA and nusB mutant strains. The Nus transcription-factors were originally identified as part of the E. coli phage λ N-protein-controlled antitermination system; hence, they were termed N-utilization substances.1 NusA, B, E and G are important for different levels of regulation within transcription and transcription:translation coupling. Their regulatory effect is often antithetic and depends on different external signals.
- DNA Length: 396 base pairs.
- DNA sequence (no stop codon):
ATG GAA ACG AAA ATC TCT TTC TCA AAA AAA CGC AAA TTG CTT ATC CAG ACG TTC TAC AAA TAC CAG CTG CTT AAC GCA AGT ATC GAC TAT ATC CAC CAG GAC ATC CTT GAC GAT GTC CAG AAT ATT AAT AAC AAG GAC GTA CTT TTT GAA ATC GAG CAA ATT GCG AAA AAA CAG ACC GAT CTG ATC AAT CAC ATC AAT ATT AAC GTG TCT TCT TCT TGG AAG TGG GAT CGC ATC CCG GCA GTC ATC CGT GCC ATT CTT ATC GTG GGT ACA TAC GAA ATT TTA TAC ACA AAT ACC CCA AAG CCA GTA ACA ATC AAT GAA ATG GTG AAG TAC GTG AAA GAA ATT GAG CCA GAT TTT GAT TAC AAA TTC GTA AAC GCT GTC TTA GAC AAG TTA GTC AAG
- Amino Acid length: 133 amino acids.
- Amino Acid sequence:
Function and Homologs
- Functional Category: Transcription
- Product: N utilization substance protein B homolog
- Module: RNA polymerase Transcriptional termination and antitermination
- Closest homologous proteins: The top (max three) homologous proteins to this protein, as identified by BLAST searches.
- transcription antitermination factor NusB [Mycoplasma mycoides], 263/100%/3e-89/100%, WP_020862503.1
- transcription antitermination factor NusB [Mycoplasma capricolum], 237/100%/1e-78/88%, WP_011386959.1
- transcription antitermination factor NusB [Mycoplasma leachii], 234/100%/1e-77/87%, WP_013447418.1
- Equivalent E. coli / JCVI functional protein: [EG10666].
- Expression Level: High
- Expression Level Hypothesis: Since it is involved in the transcription termination process, it is one of the proteins essential for the formation of the RNA polymerase antitermination complex in the presence of lambda phage N protein. It has a high expression level because it plays such an integral role in transcription. Furthermore, the nusB (groNB) gene product of Escherichia coli plays a pivotal role in allowing bacteriophage lambda N protein to function as an antiterminator of mRNA transcription and in modulating host gene expression.
- Expression Level References and Description: M. genitalium model data; annotated high in E. coli proteome
- Expression Time: Right at beginning to Early
- Expression Level Hypothesis: Based on the gene's function, the expression time must be right at beginning because the gene aids in terminating transcription and in order to create any other proteins, the gene must be expressed. RNA synthesis is a process that occurs all the time within a cell and due to this the gene requires an early expression time because without it RNA synthesis would not be able to undergo transcription.
- Expression Time References and Description: RNA polymerase is a prime example of necessary central dogma components working early in order for the cell to function. 
- Other Components: [nusA] encodes the nusA protein in mycoplasma mycoides that plays a role in termination and antitermination of RNA synthesis
- Possible Dependencies: Nucleotide Synthesis nusB termination and antitermination activity can only be effective with available ribonucleotides
- Process: RNA synthesis termination 1 2
- Inputs: RNA polymerase, mRNA (with hairpin)
- Outputs: RNA polymerase, mRNA (free)
- Synthesis Score: The synthesis score of your construct: 1, 2,3
- Predicted Translation Rate: Prediction of construct translation rate from the RBS calculator
- Design Notes and Details: For example, had to use a rare codon to fix folding energy;
- GenBank File: A link to the GenBank file. file