Analytics of Biological Sequence Data

Function of a membrane-embedded domain evolutionarily multiplied in the GPI lipid anchor pathway proteins PIG-B, PIG-M, PIG-U, PIG-W, PIG-V, and PIG-Z

Published date : 15 May 2018

Distant homology relationships among proteins with many transmembrane regions (TMs) are difficult to detect as they are clouded by the TMs’ hydrophobic compositional bias and mutational divergence in connecting loops. In the case of several GPI lipid anchor biosynthesis pathway components, the hidden evolutionary signal can be revealed with dissectHMMER, a sequence similarity search tool focusing on fold-critical, high complexity sequence segments.

type
Journal Paper
journal
Cell Cycle, Vol 17, 2018, Issue 7, doi: 10.1080/15384101.2018.1456294
Impact Factor
3.304

Charged residues next to transmembrane regions revisited: "Positive-inside rule" is complemented by the "negative inside depletion/outside enrichment rule"

Published date : 24 Jul 2017

BACKGROUND:
Transmembrane helices (TMHs) frequently occur amongst protein architectures as means for proteins to attach to or embed into biological membranes. Physical constraints such as the membrane's hydrophobicity and electrostatic potential apply uniform requirements to TMHs and their flanking regions; consequently, they are mirrored in their sequence patterns (in addition to TMHs being a span of generally hydrophobic residues) on top of variations enforced by the specific protein's biological functions.

RESULTS:

type
Journal Paper
journal
BMC Biology 2017 Jul 24;15(1):66. doi: 10.1186/s12915-017-0404-4
Impact Factor
6.779

xHMMER3x2: Utilizing HMMER3's speed and HMMER2's sensitivity and specificity in the glocal alignment mode for improved large-scale protein domain annotation

Published date : 29 Nov 2016

BACKGROUND:
While the local-mode HMMER3 is notable for its massive speed improvement, the slower glocal-mode HMMER2 is more exact for domain annotation by enforcing full domain-to-sequence alignments. Since a unit of domain necessarily implies a unit of function, local-mode HMMER3 alone remains insufficient for precise function annotation tasks. In addition, the incomparable E-values for the same domain model by different HMMER builds create difficulty when checking for domain annotation consistency on a large-scale basis.

RESULTS:

type
Journal Paper
journal
Biology Direct 2016, 11:63, DOI: 10.1186/s13062-016-0163-0
Impact Factor
3.016

The Recipe for Protein-Based Function Predition and its implementation in the ANNOTATOR Software Environment

Published date : 27 Apr 2016

As biomolecular sequencing is becoming the main technique in life sciences, functional interpretation of sequences in terms of biomolecular mechanisms with in silico approaches is getting increasingly significant. Function prediction tools are most powerful for protein-coding sequences; yet, the concepts and technologies used for this purpose are not well reflected in bioinformatics textbooks. Notably, protein sequences typically consist of globular domains and non-globular segments. The two types of regions require cardinally different approaches for function prediction.

type
Book/Book Chapter
journal
Data Mining Techniques for the Life Sciences, Vol. 1415, pg 477-506,2016, ISBN: 978-1-4939-3570-3

dissectHMMER: a HMMER-based score dissection framework that statistically evaluates fold-critical sequence segments for domain fold similarity

Published date : 01 Aug 2015

Background: Annotation transfer for function and structure within the sequence homology concept essentially requires protein sequence similarity for the secondary structural blocks forming the fold of a protein. A simplistic similarity approach in the case of non-globular segments (coiled coils, low complexity regions, transmembrane regions, long loops, etc.) is not justified and a pertinent source for mistaken homologies.

type
Journal Paper
journal
Biology Direct (2015) 10:39, doi: 10.1186/s13062-015-0068-3
Impact Factor
4.66