biology

Intimin

Intimin is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Intimin rather than just read about it. In short: Intimin is a virulence factor (adhesin) of EPEC (e.g. E. coli O127:H6) and EHEC (e.g.

Key takeaways

Intimin belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Intimin to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Intimin from memory before moving on to harder problems.

Reference excerpt

Intimin is a virulence factor (adhesin) of EPEC (e.g. E. coli O127:H6) and EHEC (e.g. E. coli O157:H7) E. coli strains. It is an attaching and effacing (A/E) protein, which with other virulence factors is necessary and responsible for enteropathogenic and enterohaemorrhagic diarrhoea. Intimin is expressed on the bacterial cell surface where it can bind to its receptor Tir (Translocated intimin receptor). Tir, and over 25 other bacterial proteins are secreted from attaching and effacing E. coli directly into the cytoplasm of intestinal epithelial cells by a Type three secretion system. Once within the cytoplasm of the host cell, Tir is inserted into the plasma membrane, allowing surface exposure and intimin binding. Tir-intimin interaction mediates tight binding of enteropathogenic and enterohaemorrhagic E.coli to the intestinal epithelia, resulting in the formation of effacing lesions on intestinal epithelia. The structure of the C-terminal domain has been solved and shown to have a C-lectin type of structure. It is the C-terminal domain that mediates attachment to Tir. It is a 94 kDa outer membrane protein encoded by eaeA gene in the locus of enterocyte effacement (LEE), a 35-Kb pathogenicity island. Mutations in the eaeA gene result in loss of ability to cause A/E lesions, and is required for full virulence in infected volunteers and animal models. The N-terminal domains of intimin from A/E lesion forming pathogens have high homology with each other and to invasin from Yersinia pseudotuberculosis and Yersinia enterocolitica, whereas the C-terminal domains show less homology. Antibodies to intimin are present in:

Immune colostrum from mothers in EPEC endemic areas The serum of EPEC/EHEC infected children and EPEC infected volunteers Secretions of Citrobacter rodentium infected mice.

References

Illustrations

Worked examples

Example 1 — a first encounter with Intimin

Start with the simplest possible case. Write down what Intimin claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Intimin before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Intimin ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Intimin

In research: Intimin appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Intimin in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Intimin is common in secondary-school and first-year university syllabi. It links to neighbouring topics Membrane channels, Microbiology stubs, Protein domains, so understanding it makes those chapters shorter.
In everyday life: Look for Intimin outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Intimin in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Intimin means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Intimin out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Intimin in simple terms?

Intimin is a virulence factor (adhesin) of EPEC (e.g. E. coli O127:H6) and EHEC (e.g.

Why does Intimin matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Intimin?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Intimin.