20 KiB
BioServices: Common Workflow Patterns
This document describes detailed multi-step workflows for common bioinformatics tasks using BioServices.
Table of Contents
- Complete Protein Analysis Pipeline
- Pathway Discovery and Network Analysis
- Compound Multi-Database Search
- Batch Identifier Conversion
- Gene Functional Annotation
- Protein Interaction Network Construction
- Multi-Organism Comparative Analysis
Complete Protein Analysis Pipeline
Goal: Given a protein name, retrieve sequence, find homologs, identify pathways, and discover interactions.
Example: Analyzing human ZAP70 protein
Step 1: UniProt Search and Identifier Retrieval
from bioservices import UniProt
u = UniProt(verbose=False)
# Search for protein by name
query = "ZAP70_HUMAN"
results = u.search(query, frmt="tab", columns="id,genes,organism,length")
# Parse results
lines = results.strip().split("\n")
if len(lines) > 1:
header = lines[0]
data = lines[1].split("\t")
uniprot_id = data[0] # e.g., P43403
gene_names = data[1] # e.g., ZAP70
print(f"UniProt ID: {uniprot_id}")
print(f"Gene names: {gene_names}")
Output:
- UniProt accession: P43403
- Gene name: ZAP70
Step 2: Sequence Retrieval
# Retrieve FASTA sequence
sequence = u.retrieve(uniprot_id, frmt="fasta")
print(sequence)
# Extract just the sequence string (remove header)
seq_lines = sequence.split("\n")
sequence_only = "".join(seq_lines[1:]) # Skip FASTA header
Output: Complete protein sequence in FASTA format
Step 3: BLAST Similarity Search
from bioservices import NCBIblast
import time
s = NCBIblast(verbose=False)
# Submit BLAST job
jobid = s.run(
program="blastp",
sequence=sequence_only,
stype="protein",
database="uniprotkb",
email="your.email@example.com"
)
print(f"BLAST Job ID: {jobid}")
# Wait for completion
while True:
status = s.getStatus(jobid)
print(f"Status: {status}")
if status == "FINISHED":
break
elif status == "ERROR":
print("BLAST job failed")
break
time.sleep(5)
# Retrieve results
if status == "FINISHED":
blast_results = s.getResult(jobid, "out")
print(blast_results[:500]) # Print first 500 characters
Output: BLAST alignment results showing similar proteins
Step 4: KEGG Pathway Discovery
from bioservices import KEGG
k = KEGG()
# Get KEGG gene ID from UniProt mapping
kegg_mapping = u.mapping(fr="UniProtKB_AC-ID", to="KEGG", query=uniprot_id)
print(f"KEGG mapping: {kegg_mapping}")
# Extract KEGG gene ID (e.g., hsa:7535)
if kegg_mapping:
kegg_gene_id = kegg_mapping[uniprot_id][0] if uniprot_id in kegg_mapping else None
if kegg_gene_id:
# Find pathways containing this gene
organism = kegg_gene_id.split(":")[0] # e.g., "hsa"
gene_id = kegg_gene_id.split(":")[1] # e.g., "7535"
pathways = k.get_pathway_by_gene(gene_id, organism)
print(f"Found {len(pathways)} pathways:")
# Get pathway names
for pathway_id in pathways:
pathway_info = k.get(pathway_id)
# Parse NAME line
for line in pathway_info.split("\n"):
if line.startswith("NAME"):
pathway_name = line.replace("NAME", "").strip()
print(f" {pathway_id}: {pathway_name}")
break
Output:
- path:hsa04064 - NF-kappa B signaling pathway
- path:hsa04650 - Natural killer cell mediated cytotoxicity
- path:hsa04660 - T cell receptor signaling pathway
- path:hsa04662 - B cell receptor signaling pathway
Step 5: Protein-Protein Interactions
from bioservices import PSICQUIC
p = PSICQUIC()
# Query MINT database for human (taxid:9606) interactions
query = f"ZAP70 AND species:9606"
interactions = p.query("mint", query)
# Parse PSI-MI TAB format results
if interactions:
interaction_lines = interactions.strip().split("\n")
print(f"Found {len(interaction_lines)} interactions")
# Print first few interactions
for line in interaction_lines[:5]:
fields = line.split("\t")
protein_a = fields[0]
protein_b = fields[1]
interaction_type = fields[11]
print(f" {protein_a} - {protein_b}: {interaction_type}")
Output: List of proteins that interact with ZAP70
Step 6: Gene Ontology Annotation
from bioservices import QuickGO
g = QuickGO()
# Get GO annotations for protein
annotations = g.Annotation(protein=uniprot_id, format="tsv")
if annotations:
# Parse TSV results
lines = annotations.strip().split("\n")
print(f"Found {len(lines)-1} GO annotations")
# Display first few annotations
for line in lines[1:6]: # Skip header
fields = line.split("\t")
go_id = fields[6]
go_term = fields[7]
go_aspect = fields[8]
print(f" {go_id}: {go_term} [{go_aspect}]")
Output: GO terms annotating ZAP70 function, process, and location
Complete Pipeline Summary
Inputs: Protein name (e.g., "ZAP70_HUMAN")
Outputs:
- UniProt accession and gene name
- Protein sequence (FASTA)
- Similar proteins (BLAST results)
- Biological pathways (KEGG)
- Interaction partners (PSICQUIC)
- Functional annotations (GO terms)
Script: scripts/protein_analysis_workflow.py automates this entire pipeline.
Pathway Discovery and Network Analysis
Goal: Analyze all pathways for an organism and extract protein interaction networks.
Example: Human (hsa) pathway analysis
Step 1: Get All Pathways for Organism
from bioservices import KEGG
k = KEGG()
k.organism = "hsa"
# Get all pathway IDs
pathway_ids = k.pathwayIds
print(f"Found {len(pathway_ids)} pathways for {k.organism}")
# Display first few
for pid in pathway_ids[:10]:
print(f" {pid}")
Output: List of ~300 human pathways
Step 2: Parse Pathway for Interactions
# Analyze specific pathway
pathway_id = "hsa04660" # T cell receptor signaling
# Get KGML data
kgml_data = k.parse_kgml_pathway(pathway_id)
# Extract entries (genes/proteins)
entries = kgml_data['entries']
print(f"Pathway contains {len(entries)} entries")
# Extract relations (interactions)
relations = kgml_data['relations']
print(f"Found {len(relations)} relations")
# Analyze relation types
relation_types = {}
for rel in relations:
rel_type = rel.get('name', 'unknown')
relation_types[rel_type] = relation_types.get(rel_type, 0) + 1
print("\nRelation type distribution:")
for rel_type, count in sorted(relation_types.items()):
print(f" {rel_type}: {count}")
Output:
- Entry count (genes/proteins in pathway)
- Relation count (interactions)
- Distribution of interaction types (activation, inhibition, binding, etc.)
Step 3: Extract Protein-Protein Interactions
# Filter for specific interaction types
pprel_interactions = [
rel for rel in relations
if rel.get('link') == 'PPrel' # Protein-protein relation
]
print(f"Found {len(pprel_interactions)} protein-protein interactions")
# Extract interaction details
for rel in pprel_interactions[:10]:
entry1 = rel['entry1']
entry2 = rel['entry2']
interaction_type = rel.get('name', 'unknown')
print(f" {entry1} -> {entry2}: {interaction_type}")
Output: Directed protein-protein interactions with types
Step 4: Convert to Network Format (SIF)
# Get Simple Interaction Format (filters for key interactions)
sif_data = k.pathway2sif(pathway_id)
# SIF format: source, interaction_type, target
print("\nSimple Interaction Format:")
for interaction in sif_data[:10]:
print(f" {interaction}")
Output: Network edges suitable for Cytoscape or NetworkX
Step 5: Batch Analysis of All Pathways
import pandas as pd
# Analyze all pathways (this takes time!)
all_results = []
for pathway_id in pathway_ids[:50]: # Limit for example
try:
kgml = k.parse_kgml_pathway(pathway_id)
result = {
'pathway_id': pathway_id,
'num_entries': len(kgml.get('entries', [])),
'num_relations': len(kgml.get('relations', []))
}
all_results.append(result)
except Exception as e:
print(f"Error parsing {pathway_id}: {e}")
# Create DataFrame
df = pd.DataFrame(all_results)
print(df.describe())
# Find largest pathways
print("\nLargest pathways:")
print(df.nlargest(10, 'num_entries')[['pathway_id', 'num_entries', 'num_relations']])
Output: Statistical summary of pathway sizes and interaction densities
Script: scripts/pathway_analysis.py implements this workflow with export options.
Compound Multi-Database Search
Goal: Search for compound by name and retrieve identifiers across KEGG, ChEBI, and ChEMBL.
Example: Geldanamycin (antibiotic)
Step 1: Search KEGG Compound Database
from bioservices import KEGG
k = KEGG()
# Search by compound name
compound_name = "Geldanamycin"
results = k.find("compound", compound_name)
print(f"KEGG search results for '{compound_name}':")
print(results)
# Extract compound ID
if results:
lines = results.strip().split("\n")
if lines:
kegg_id = lines[0].split("\t")[0] # e.g., cpd:C11222
kegg_id_clean = kegg_id.replace("cpd:", "") # C11222
print(f"\nKEGG Compound ID: {kegg_id_clean}")
Output: KEGG ID (e.g., C11222)
Step 2: Get KEGG Entry with Database Links
# Retrieve compound entry
compound_entry = k.get(kegg_id)
# Parse entry for database links
chebi_id = None
for line in compound_entry.split("\n"):
if "ChEBI:" in line:
# Extract ChEBI ID
parts = line.split("ChEBI:")
if len(parts) > 1:
chebi_id = parts[1].strip().split()[0]
print(f"ChEBI ID: {chebi_id}")
break
# Display entry snippet
print("\nKEGG Entry (first 500 chars):")
print(compound_entry[:500])
Output: ChEBI ID (e.g., 5292) and compound information
Step 3: Cross-Reference to ChEMBL via UniChem
from bioservices import UniChem
u = UniChem()
# Convert KEGG → ChEMBL
try:
chembl_id = u.get_compound_id_from_kegg(kegg_id_clean)
print(f"ChEMBL ID: {chembl_id}")
except Exception as e:
print(f"UniChem lookup failed: {e}")
chembl_id = None
Output: ChEMBL ID (e.g., CHEMBL278315)
Step 4: Retrieve Detailed Information
# Get ChEBI information
if chebi_id:
from bioservices import ChEBI
c = ChEBI()
try:
chebi_entity = c.getCompleteEntity(f"CHEBI:{chebi_id}")
print(f"\nChEBI Formula: {chebi_entity.Formulae}")
print(f"ChEBI Name: {chebi_entity.chebiAsciiName}")
except Exception as e:
print(f"ChEBI lookup failed: {e}")
# Get ChEMBL information
if chembl_id:
from bioservices import ChEMBL
chembl = ChEMBL()
try:
chembl_compound = chembl.get_compound_by_chemblId(chembl_id)
print(f"\nChEMBL Molecular Weight: {chembl_compound['molecule_properties']['full_mwt']}")
print(f"ChEMBL SMILES: {chembl_compound['molecule_structures']['canonical_smiles']}")
except Exception as e:
print(f"ChEMBL lookup failed: {e}")
Output: Chemical properties from multiple databases
Complete Compound Workflow Summary
Input: Compound name (e.g., "Geldanamycin")
Output:
- KEGG ID: C11222
- ChEBI ID: 5292
- ChEMBL ID: CHEMBL278315
- Chemical formula
- Molecular weight
- SMILES structure
Script: scripts/compound_cross_reference.py automates this workflow.
Batch Identifier Conversion
Goal: Convert multiple identifiers between databases efficiently.
Batch UniProt → KEGG Mapping
from bioservices import UniProt
u = UniProt()
# List of UniProt IDs
uniprot_ids = ["P43403", "P04637", "P53779", "Q9Y6K9"]
# Batch mapping (comma-separated)
query_string = ",".join(uniprot_ids)
results = u.mapping(fr="UniProtKB_AC-ID", to="KEGG", query=query_string)
print("UniProt → KEGG mapping:")
for uniprot_id, kegg_ids in results.items():
print(f" {uniprot_id} → {kegg_ids}")
Output: Dictionary mapping each UniProt ID to KEGG gene IDs
Batch File Processing
import csv
# Read identifiers from file
def read_ids_from_file(filename):
with open(filename, 'r') as f:
ids = [line.strip() for line in f if line.strip()]
return ids
# Process in chunks (API limits)
def batch_convert(ids, from_db, to_db, chunk_size=100):
u = UniProt()
all_results = {}
for i in range(0, len(ids), chunk_size):
chunk = ids[i:i+chunk_size]
query = ",".join(chunk)
try:
results = u.mapping(fr=from_db, to=to_db, query=query)
all_results.update(results)
print(f"Processed {min(i+chunk_size, len(ids))}/{len(ids)}")
except Exception as e:
print(f"Error processing chunk {i}: {e}")
return all_results
# Write results to CSV
def write_mapping_to_csv(mapping, output_file):
with open(output_file, 'w', newline='') as f:
writer = csv.writer(f)
writer.writerow(['Source_ID', 'Target_IDs'])
for source_id, target_ids in mapping.items():
target_str = ";".join(target_ids) if target_ids else "No mapping"
writer.writerow([source_id, target_str])
# Example usage
input_ids = read_ids_from_file("uniprot_ids.txt")
mapping = batch_convert(input_ids, "UniProtKB_AC-ID", "KEGG", chunk_size=50)
write_mapping_to_csv(mapping, "uniprot_to_kegg_mapping.csv")
Script: scripts/batch_id_converter.py provides command-line batch conversion.
Gene Functional Annotation
Goal: Retrieve comprehensive functional information for a gene.
Workflow
from bioservices import UniProt, KEGG, QuickGO
# Gene of interest
gene_symbol = "TP53"
# 1. Find UniProt entry
u = UniProt()
search_results = u.search(f"gene:{gene_symbol} AND organism:9606",
frmt="tab",
columns="id,genes,protein names")
# Extract UniProt ID
lines = search_results.strip().split("\n")
if len(lines) > 1:
uniprot_id = lines[1].split("\t")[0]
protein_name = lines[1].split("\t")[2]
print(f"Protein: {protein_name}")
print(f"UniProt ID: {uniprot_id}")
# 2. Get KEGG pathways
kegg_mapping = u.mapping(fr="UniProtKB_AC-ID", to="KEGG", query=uniprot_id)
if uniprot_id in kegg_mapping:
kegg_id = kegg_mapping[uniprot_id][0]
k = KEGG()
organism, gene_id = kegg_id.split(":")
pathways = k.get_pathway_by_gene(gene_id, organism)
print(f"\nPathways ({len(pathways)}):")
for pathway_id in pathways[:5]:
print(f" {pathway_id}")
# 3. Get GO annotations
g = QuickGO()
go_annotations = g.Annotation(protein=uniprot_id, format="tsv")
if go_annotations:
lines = go_annotations.strip().split("\n")
print(f"\nGO Annotations ({len(lines)-1} total):")
# Group by aspect
aspects = {"P": [], "F": [], "C": []}
for line in lines[1:]:
fields = line.split("\t")
go_aspect = fields[8] # P, F, or C
go_term = fields[7]
aspects[go_aspect].append(go_term)
print(f" Biological Process: {len(aspects['P'])} terms")
print(f" Molecular Function: {len(aspects['F'])} terms")
print(f" Cellular Component: {len(aspects['C'])} terms")
# 4. Get protein sequence features
full_entry = u.retrieve(uniprot_id, frmt="txt")
print("\nProtein Features:")
for line in full_entry.split("\n"):
if line.startswith("FT DOMAIN"):
print(f" {line}")
Output: Comprehensive annotation including name, pathways, GO terms, and features.
Protein Interaction Network Construction
Goal: Build a protein-protein interaction network for a set of proteins.
Workflow
from bioservices import PSICQUIC
import networkx as nx
# Proteins of interest
proteins = ["ZAP70", "LCK", "LAT", "SLP76", "PLCg1"]
# Initialize PSICQUIC
p = PSICQUIC()
# Build network
G = nx.Graph()
for protein in proteins:
# Query for human interactions
query = f"{protein} AND species:9606"
try:
results = p.query("intact", query)
if results:
lines = results.strip().split("\n")
for line in lines:
fields = line.split("\t")
# Extract protein names (simplified)
protein_a = fields[4].split(":")[1] if ":" in fields[4] else fields[4]
protein_b = fields[5].split(":")[1] if ":" in fields[5] else fields[5]
# Add edge
G.add_edge(protein_a, protein_b)
except Exception as e:
print(f"Error querying {protein}: {e}")
print(f"Network: {G.number_of_nodes()} nodes, {G.number_of_edges()} edges")
# Analyze network
print("\nNode degrees:")
for node in proteins:
if node in G:
print(f" {node}: {G.degree(node)} interactions")
# Export for visualization
nx.write_gml(G, "protein_network.gml")
print("\nNetwork exported to protein_network.gml")
Output: NetworkX graph exported in GML format for Cytoscape visualization.
Multi-Organism Comparative Analysis
Goal: Compare pathway or gene presence across multiple organisms.
Workflow
from bioservices import KEGG
k = KEGG()
# Organisms to compare
organisms = ["hsa", "mmu", "dme", "sce"] # Human, mouse, fly, yeast
organism_names = {
"hsa": "Human",
"mmu": "Mouse",
"dme": "Fly",
"sce": "Yeast"
}
# Pathway of interest
pathway_name = "cell cycle"
print(f"Searching for '{pathway_name}' pathway across organisms:\n")
for org in organisms:
k.organism = org
# Search pathways
results = k.lookfor_pathway(pathway_name)
print(f"{organism_names[org]} ({org}):")
if results:
for pathway in results[:3]: # Show first 3
print(f" {pathway}")
else:
print(" No matches found")
print()
Output: Pathway presence/absence across organisms.
Best Practices for Workflows
1. Error Handling
Always wrap service calls:
try:
result = service.method(params)
if result:
# Process
pass
except Exception as e:
print(f"Error: {e}")
2. Rate Limiting
Add delays for batch processing:
import time
for item in items:
result = service.query(item)
time.sleep(0.5) # 500ms delay
3. Result Validation
Check for empty or unexpected results:
if result and len(result) > 0:
# Process
pass
else:
print("No results returned")
4. Progress Reporting
For long workflows:
total = len(items)
for i, item in enumerate(items):
# Process item
if (i + 1) % 10 == 0:
print(f"Processed {i+1}/{total}")
5. Data Export
Save intermediate results:
import json
with open("results.json", "w") as f:
json.dump(results, f, indent=2)
Integration with Other Tools
BioPython Integration
from bioservices import UniProt
from Bio import SeqIO
from io import StringIO
u = UniProt()
fasta_data = u.retrieve("P43403", "fasta")
# Parse with BioPython
fasta_io = StringIO(fasta_data)
record = SeqIO.read(fasta_io, "fasta")
print(f"Sequence length: {len(record.seq)}")
print(f"Description: {record.description}")
Pandas Integration
from bioservices import UniProt
import pandas as pd
from io import StringIO
u = UniProt()
results = u.search("zap70", frmt="tab", columns="id,genes,length,organism")
# Load into DataFrame
df = pd.read_csv(StringIO(results), sep="\t")
print(df.head())
print(df.describe())
NetworkX Integration
See Protein Interaction Network Construction above.
For complete working examples, see the scripts in scripts/ directory.