text: from django.db import models
  
  
  class Protein(models.Model):
      """Reference protein sequence"""
      ref_id = models.CharField('Reference ID', max_length=20, unique=True)
      description = models.CharField('Description', max_length=255)
      gene = models.CharField('Gene symbol', max_length=30, blank=True)
      ec_number = models.CharField('EC number', max_length=100, blank=True)
      flag = models.CharField('Flag', max_length=20, blank=True)
      organism = models.CharField('Organism', max_length=255)
      source_db = models.CharField('Source DB', max_length=20)
      sequence = models.TextField('Sequence')
  
      def __str__(self):
          return f"<Protein {self.ref_id} {self.description}>"
  