biology

HAAAP family

HAAAP 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 HAAAP family rather than just read about it. In short: The Hydroxy/Aromatic Amino Acid Permease (HAAAP) Family (TC# 2.A.42) is a member of the large Amino Acid-Polyamine-OrganoCation (APC) Superfamily of secondary carrier proteins. Members of the HAAAP family all function in amino acid uptake.

Key takeaways

HAAAP 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 HAAAP family to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HAAAP family from memory before moving on to harder problems.

Reference excerpt

The Hydroxy/Aromatic Amino Acid Permease (HAAAP) Family (TC# 2.A.42) is a member of the large Amino Acid-Polyamine-OrganoCation (APC) Superfamily of secondary carrier proteins. Members of the HAAAP family all function in amino acid uptake. Homologues are present in many Gram-negative and Gram-positive bacteria, with at least one member classified from archaea (TC# 2.A.42.1.7, Thermococcus barophilus).

Structure Proteins of the HAAAP family possess 403-443 amino acyl residues and exhibit eleven putative or established TransMembrane α-helical Spanners (TMSs). These proteins exhibit topological features common to the eukaryotic amino acid/auxin permease (AAAP) family (TC# 2.A.18). These proteins also exhibit limited sequence similarity with some of the AAAP family members. A phylogenetic relationship has been proposed between members of the HAP family and the APC family since they exhibit limited sequence similarity with one another. As of early 2016, no crystal structural data is available for members of the HAAAP family in RCSB.

Members The HAAAP family includes three well-characterized aromatic amino acid/H+ symport permeases of E. coli and two hydroxy amino acid permeases. The aromatic amino acid/H+ symport permeases are:

Mtr, a high affinity tryptophan-specific permease (TC# 2.A.42.1.2). TnaB, a low affinity tryptophan permease (TC# 2.A.42.1.3). TyrP, a tyrosine-specific permease (TC# 2.A.42.1.1). The two hydroxy amino acid permeases are:

SdaC, the serine permease (TC# 2.A.42.2.1), of E. coli. SdaC of E. coli (TC# 2.A.42.2.1) is also called DcrA, and together with a periplasmic protein DcrB (P37620), has been reported to play a role in phage DNA uptake in conjunction with an outer membrane receptors of the OMR family (TC# 1.B.14). TdcC, the threonine permease (TC# 2.A.42.2.2), of E. coli. Thus, FhuA (TC# 1.B.14.1.4) transports phage T5 DNA while BtuB (TC# 1.B.14.3.1) transports phage C1 DNA (Samsonov et al., 2002). DcuB is a putative lipoprotein found only in enteric bacteria. All members of the HAAAP family can be found in the Transporter Classification Database.

Transport Reaction The generalized transport reaction catalyzed by proteins of the HAAAP family is: Amino acid (out) + nH+ (out) → Amino acid (in) + nH+ (in).

References

As of 26 January 2016, this article is derived in whole or in part from Transporter Classification Database. The copyright holder has licensed the content in a manner that permits reuse under CC BY-SA 3.0 and GFDL. All relevant terms must be followed. The original text was at "2.A.42 The Hydroxy/Aromatic Amino Acid Permease (HAAAP) Family"

Worked examples

Example 1 — a first encounter with HAAAP family

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

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

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

Frequently asked questions

What is HAAAP family in simple terms?

Why does HAAAP 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 HAAAP 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 HAAAP family.