biology

LACTB

LACTB 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 LACTB rather than just read about it. In short: Serine beta-lactamase-like protein LACTB, mitochondrial is an enzyme that in humans is encoded by the LACTB gene. This gene encodes a 54 kDa protein sharing significant sequence similarity to serine proteases of the penicillin binding protein and beta-lactamase superfamily occurring in bacteria.

Key takeaways

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

Reference excerpt

Serine beta-lactamase-like protein LACTB, mitochondrial is an enzyme that in humans is encoded by the LACTB gene. This gene encodes a 54 kDa protein sharing significant sequence similarity to serine proteases of the penicillin binding protein and beta-lactamase superfamily occurring in bacteria. It is involved in the regulation of the metabolic circuitry. A causal association has been found between LACTB and obesity. In breast cancer, LACTB has a tumor suppressor function by modulating lipid metabolism.

Structure

Gene The LACTB gene is located at chromosome 15q22.1, consisting of 8 exons. Alternative splicing results in multiple transcript variants encoding different protein isoforms.

Protein LACTB shares sequence similarity to the beta-lactamase/penicillin-binding protein family of serine proteases that are involved in bacterial cell wall metabolism. The N-terminal 97 amino acid segment of LACTB does not form part of the conserved penicillin-binding protein domain and may therefore be responsible for organelle targeting.

Function LACTB is widely expressed in different mammalian tissues, with the predominant expression in human skeletal muscle. It localizes in the mitochondrial intermembrane space. LACTB can polymerize into stable filaments occupying the mitochondrial intermembrane space. These filaments are speculated to play a role in submitochondrial organization and therefore possibly affect mitochondrial metabolon organization.

Clinical significance It has been found LACTB could cause obesity through gene co-expression analysis based on data integrated from multiple sources. This has been validated in vivo through LACTB overexpression in transgenic mice, which resulted in an obese phenotype. LACTB has also been identified to be a tumor suppressor through its effect on mitochondrial phospholipid metabolism and modulation of cell differentiation state.

Interactions MiR-125b-5p

References

Illustrations

Worked examples

Example 1 — a first encounter with LACTB

Start with the simplest possible case. Write down what LACTB 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 LACTB 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 LACTB 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 LACTB

In research: LACTB 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 LACTB 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: LACTB is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genes on human chromosome 15, Human chromosome 15 gene stubs, so understanding it makes those chapters shorter.
In everyday life: Look for LACTB 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 LACTB in 20 minutes

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

Frequently asked questions

What is LACTB in simple terms?

Why does LACTB 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 LACTB?

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 LACTB.