Design a ribosome binding site (OSTIR)
rbs_designDesign a 5' UTR / ribosome binding site for a given CDS. Generates a spread of Shine-Dalgarno cores and SD-to-start spacings, scores every one with OSTIR in the context of your own CDS (which matters — the rate depends on how the RBS interacts with that CDS's 5' folding), and returns them ranked. Supply targetExpression to rank by closeness to a target rate instead of by maximum strength, and supply your existing 5' UTR to get a measured baseline and fold-change for each candidate. Runs ViennaRNA on a shared service and is therefore rate limited (see 429/503). PREDICTED, NOT MEASURED (Spearman ρ = 0.39 on two 5' UTR datasets it was not fitted to). Spearman ρ = 0.39 against measured expression on two 5' UTR datasets it was not fitted to (Gilliot & Gorochowski, Nucleic Acids Res 2024;52(13):e58). The widely quoted 53% within 2-fold / 91% within 10-fold are calibration residuals on the fitting set, not held-out validation. Valid for: translation INITIATION only, in E. coli-like Gram-negative hosts (the model is parameterised on the E. coli anti-Shine-Dalgarno sequence). Rankings within one construct context; the absolute value has no units and no meaning.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cds | Yes | Coding sequence, raw or FASTA, starting at its start codon. Only the 5' end affects the prediction, so the first ~90 nt is enough. A, C, G, T/U only. Max 3,000 nt. | |
| limit | No | How many ranked candidates to return. 1-60. | |
| leader | No | Optional 5' context upstream of the designed RBS — the transcribed leader from your promoter. Affects the standby-site term. Defaults to a 20 nt unstructured poly-A leader. | |
| currentUtr | No | Optional: your existing 5' UTR (everything upstream of the start codon). Scored as a baseline so each candidate gets a fold-change against it. | |
| targetExpression | No | Optional target rate on OSTIR's arbitrary scale. Candidates are then ranked by closeness to it (log-ratio) rather than by maximum strength. Only meaningful against a number produced by this same tool. | |
| antiShineDalgarno | No | Optional anti-Shine-Dalgarno sequence (the 16S rRNA 3' end) to model a non-E. coli host. Omit to use OSTIR's own E. coli default. |