biology

Holin superfamily III

Holin superfamily III 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 Holin superfamily III rather than just read about it. In short: The Holin Superfamily III is a superfamily of integral membrane transport proteins. It is one of the seven different holin superfamilies in total.

Key takeaways

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

Reference excerpt

The Holin Superfamily III is a superfamily of integral membrane transport proteins. It is one of the seven different holin superfamilies in total. In general, these proteins are thought to play a role in regulated cell death, although functionality varies between families and individual members. Members of the holin superfamily III are derived from Pseudomonadota, Synergistota, Actinomycetota, Deinococcota, and Archaea. This superfamily includes seven TC families:

1.E.2 - The λ Holin S (λ Holin) Family 1.E.3 - The P2 Holin (P2 Holin) Family 1.E.4 - The LydA Holin (LydA Holin) Family 1.E.5 - The PRD1 Phage P35 Holin (P35 Holin) Family 1.E.20 - The Pseudomonas aeruginosa Hol Holin (Hol Holin) Family 1.E.34 - The Putative Actinobacterial Holin-X (Hol-X) Family 1.E.41 - The Deinococcus/Thermus Holin (D/T-Hol) Family Members of all families (with the exception of the Hol-X family; TC# 1.E.34) appear to have three transmembrane segments (TMSs). Members of the Hol-X family appear to have two putative TMSs. The missing TMS in family 34 proteins is the N-terminal TMS as revealed by multiple alignments. These seven families have average sizes of 110, 96, 105, 112, 143, 159 and 108 amino acyl residues (aas), respectively. Notice that the only family with members predicted to have just two TMSs is the one containing the largest homologues; this is due to hydrophilic extensions. The average size of proteins in the entire superfamily is 114 aas with a standard deviation o 23 aas.

See also Holin Lysin Transporter Classification Database

References

Worked examples

Example 1 — a first encounter with Holin superfamily III

Start with the simplest possible case. Write down what Holin superfamily III 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 Holin superfamily III 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 Holin superfamily III 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 Holin superfamily III

In research: Holin superfamily III 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 Holin superfamily III 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: Holin superfamily III is common in secondary-school and first-year university syllabi. It links to neighbouring topics Holins, Membrane protein stubs, Protein superfamilies, so understanding it makes those chapters shorter.
In everyday life: Look for Holin superfamily III 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 Holin superfamily III in 20 minutes

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

Frequently asked questions

What is Holin superfamily III in simple terms?

The Holin Superfamily III is a superfamily of integral membrane transport proteins. It is one of the seven different holin superfamilies in total.

Why does Holin superfamily III 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 Holin superfamily III?

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 Holin superfamily III.