Post-translational modifications (PTMs)
Although much fewer bacterial proteins seem to have post-translational modifications (PTMs) compared to eukaryotic proteins, a substantial number of proteins are modified in E. coli. For instance, Potel et al. (2018) found 227 phosphoproteins of which 173 were phosphorylated on histidine. Interestingly, the majority of phosphorylated amino acids were serine (1,220 sites) with only 246 sites on histidine and 501 phosphorylated theronines and 162 tyrosines. Interactome
The interactome of E. coli has been studied by affinity purification and mass spectrometry (AP/MS) and by analyzing the binary interactions among its proteins. Protein complexes. A 2006 study purified 4,339 proteins from cultures of strain K-12 and found interacting partners for 2,667 proteins, many of which had unknown functions at the time. A 2009 study found 5,993 interactions between proteins of the same E. coli strain, though these data showed little overlap with those of the 2006 publication.Binary interactions. Rajagopala et al. (2014) have carried out systematic yeast two-hybrid screens with most E. coli proteins, and found a total of 2,234 protein-protein interactions. This study also integrated genetic interactions and protein structures and mapped 458 interactions within 227 protein complexes. Normal microbiota
E. coli belongs to a group of bacteria informally known as coliforms that are found in the gastrointestinal tract of warm-blooded animals. E. coli normally colonizes an infants gastrointestinal tract within 40 hours of birth, arriving with food or water or from the individuals handling the child. In the bowel, E. coli adheres to the mucus of the large intestine.
Genome-wide association studies have since added to understanding of the genomics and pathogenesis of the disease. More than 200 single nucleotide polymorphisms (SNPs or "snips") are now known to be associated with susceptibility to IBD. One of the largest genetic studies of IBD was published in 2012 . The analysis explained more of the variance in Crohns disease and ulcerative colitis than previously reported. The results suggested that commensal microbiota are altered in such a way that they act as pathogens in inflammatory bowel diseases. Other studies show that mutations in IBD-associated genes might interfere with the cellular activity and interactions with the microbiome that promote normal immune responses. Many studies identified that microRNAs dysregulation involved in IBD and to promote colorectal cancer. By 2020, single-cell RNA sequencing analysis was launched by a small consortium using IBD patient biopsy material in a search for therapeutic targets. Diagnosis
The diagnosis is usually confirmed by biopsies on colonoscopy. Fecal calprotectin is useful as an initial investigation, which may suggest the possibility of IBD, as this test is sensitive but not specific for IBD.