biology

Hol118 family

Hol118 family 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 Hol118 family rather than just read about it. In short: The Listeria Phage A118 Holin (Hol118) Family (TC# 1.E.21) is a group of transporters belonging to the Holin Superfamily V. A representative list of proteins belonging to the Hol118 family can be found in the Transporter Classification Database.

Key takeaways

Hol118 family belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Hol118 family to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Hol118 family from memory before moving on to harder problems.

Reference excerpt

The Listeria Phage A118 Holin (Hol118) Family (TC# 1.E.21) is a group of transporters belonging to the Holin Superfamily V. A representative list of proteins belonging to the Hol118 family can be found in the Transporter Classification Database. Listeria monocytogenes bacteriophage A118 encodes a native holin, hol118, of 93 amino acyl residues (aas) exhibiting 3 putative transmembrane segments (TMSs). When cloned into lambda phage devoid of the S holin, it caused very late cell lysis, beginning 80 min. after induction. Hol118 appeared in the cytoplasmic membrane shortly after infection. A second translational start codon (AUG-3) at nucleotide position 40 in the gene gives rise to a second gene product of 83 aas lacking TMS-1 (Hol118(83)). It is produced with the full length protein, appears in the membrane, but cannot support lambda lysis and inhibits lysis by Hol118. This dominant inhibitor presumably determines the time of lysis. A homologue is found in L. innocua.

The reaction probably catalyzed is:small molecules + autolysin (in) → small molecules + autolysin (out)

See also Holin Lysin Transporter Classification Database

Further reading EMBL-EBI, InterPro. "Bacteriophage A118, holin (IPR009708) < InterPro < EMBL-EBI". www.ebi.ac.uk. Retrieved 2016-03-21. Kuo, Cheng-Yi; Sinha, Shubhra; Jazayeri, Jalal A.; Pouton, Colin W. (2009). "A stably engineered, suicidal strain of listeria monocytogenes delivers protein and/or DNA to fully differentiated intestinal epithelial monolayers". Molecular Pharmaceutics. 6 (4): 1052–1061. doi:10.1021/mp800153u. PMID 19317435.

References

As of this edit, this article uses content from "1.E.21 The Listeria Phage A118 Holin (Hol118) Family", which is licensed in a way that permits reuse under the Creative Commons Attribution-ShareAlike 3.0 Unported License, but not under the GFDL. All relevant terms must be followed.

Worked examples

Example 1 — a first encounter with Hol118 family

Start with the simplest possible case. Write down what Hol118 family 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 Hol118 family 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 Hol118 family 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 Hol118 family

In research: Hol118 family 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 Hol118 family 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: Hol118 family is common in secondary-school and first-year university syllabi. It links to neighbouring topics Holins, Protein families, so understanding it makes those chapters shorter.
In everyday life: Look for Hol118 family 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 Hol118 family in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hol118 family 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 Hol118 family out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hol118 family in simple terms?

Why does Hol118 family 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 Hol118 family?

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 Hol118 family.