In the modern genomic era, scientists without extensive bioinformatic training need to apply high-power computational analyses to critical tasks like phage genome annotation. At the Center for Phage Technology (CPT), we developed a suite of phage-oriented tools housed in open, user-friendly web-based interfaces. A Galaxy platform conducts computationally intensive analyses and Apollo, a collaborative genome annotation editor, visualizes the results of these analyses. The collection includes open source applications such as the BLAST+ suite, InterProScan, and several gene callers, as well as unique tools developed at the CPT that allow maximum user flexibility. We describe in detail programs for finding Shine-Dalgarno sequences, resources used for confident identification of lysis genes such as spanins, and methods used for identifying interrupted genes that contain frameshifts or introns. At the CPT, genome annotation is separated into two robust segments that are facilitated through the automated execution of many tools chained together in an operation called a workflow. First, the structural annotation workflow results in gene and other feature calls. This is followed by a functional annotation workflow that combines sequence comparisons and conserved domain searching, which is contextualized to allow integrated evidence assessment in functional prediction. Finally, we describe a workflow used for comparative genomics. Using this multi-purpose platform enables researchers to easily and accurately annotate an entire phage genome. The portal can be accessed at https://cpt.tamu.edu/galaxy-pub with accompanying user training material.
Phage Genome Annotation: Where to Begin and End
