Structure of α-keratin: Structural implication of the amino acid sequences of the type I and type II chain segments

1977 ◽  
Vol 113 (2) ◽  
pp. 449-454 ◽  
Author(s):  
D.A.D. Parry ◽  
W.G. Crewther ◽  
R.D.B. Fraser ◽  
T.P. MacRae
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Type I ◽  
Type Ii

scholarly journals Amino acid sequences of α-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment

1978 ◽  
Vol 173 (2) ◽  
pp. 365-371 ◽  
Author(s):  
W G Crewther ◽  
A S Inglis ◽  
N M McKern
Keyword(s):  
Amino Acid ◽  
Coiled Coil ◽  
Complete Sequence ◽  
Amino Acid Sequences ◽  
Helical Axis ◽  
Type I ◽  
Type Ii ◽  
Coil Structure ◽  
Aqueous Urea ◽  
Alpha Keratin

1. The helical fragments obtained by partial chymotryptic digestion of S-carboxymethylkeratine-A, the low-sulphur fraction from wool, were fractionated into type-I and type-II helical segments in aqueous urea under conditions limiting carbamoylation. 2. The amino acid sequence of a 109-residue type-II segment was completed by using the sequenator. 3. When the data were incorporated into a helical model of 3.6 residues per turn the hydrophobic residues generated a band aligned at a slight angle to the helical axis. This result is in accord with the postulated coiled-coil structure of the crystalline regions of alpha-keratin.

scholarly journals Amino acid sequences of α-helical segments from S-carbosymethylkerateine-A. Complete sequence of a type-I segment

1978 ◽  
Vol 173 (2) ◽  
pp. 373-385 ◽  
Author(s):  
K H Gough ◽  
A S Inglis ◽  
W G Crewther
Keyword(s):  
Amino Acid ◽  
Sequence Data ◽  
Coiled Coil ◽  
Alpha Helix ◽  
Protein S ◽  
Amino Acid Sequences ◽  
Type I ◽  
Type Ii ◽  
Sequencing Data ◽  
Helical Segment

The amino acid sequence of a type-I helical segment from the low-sulphur protein (S-carboxymethylkerateine-A) of wool was determined by combining automatic and manual-sequencing data. Whereas in the type-II helical segment most of the cationic groups occur in pairs, 11 of the 22 anionic residues in the sequence of the type-I segment were situated next to a second anionic residue. This suggests possible interactions between type-I and type-II helical segments in alpha-keratin. As observed with the sequence of a type-II helical segment a model constructed on 3.6 residues per turn of helix shows a line of hydrophobic residues along the helix, thereby supporting the physicochemical evidence that the molecule is predominantly helical and forms part of a coiled-coil structure. Examination of the sequence data by predictive methods indicates the possibilty of extensive sections of alpha-helix interspersed with discontinuities. The molecule contains a number of regions with peptide sequences identical with those found by other workers after enzymic digestion of fractions from oxidized wool.

scholarly journals Seven new mutations in the nicotinamide adenine dinucleotide reduced–cytochrome b5 reductase gene leading to methemoglobinemia type I

Blood ◽  
2001 ◽  
Vol 97 (4) ◽  
pp. 1106-1114 ◽  
Author(s):  
Jan Dekker ◽  
Michel H. M. Eppink ◽  
Rob van Zwieten ◽  
Thea de Rijk ◽  
Angel F. Remacha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nicotinamide Adenine Dinucleotide ◽  
Cytochrome B5 ◽  
Enzyme Inactivation ◽  
Amino Acid Substitutions ◽  
Type I ◽  
Type Ii ◽  
3 Dimensional ◽  
Cytochrome B5 Reductase ◽  
Fad Binding

Abstract Cytochrome b5 reductase (b5R) deficiency manifests itself in 2 distinct ways. In methemoglobinemia type I, the patients only suffer from cyanosis, whereas in type II, the patients suffer in addition from severe mental retardation and neurologic impairment. Biochemical data indicate that this may be due to a difference in mutations, causing enzyme instability in type I and complete enzyme deficiency or enzyme inactivation in type II. We have investigated 7 families with methemoglobulinemia type I and found 7 novel mutations in the b5R gene. Six of these mutations predicted amino acid substitutions at sites not involved in reduced nicotinamide adenine dinucleotide (NADH) or flavin adenine dinucleotide (FAD) binding, as deduced from a 3-dimensional model of human b5R. This model was constructed from comparison with the known 3-dimensional structure of pig b5R. The seventh mutation was a splice site mutation leading to skipping of exon 5 in messenger RNA, present in heterozygous form in a patient together with a missense mutation on the other allele. Eight other amino acid substitutions, previously described to cause methemoglobinemia type I, were also situated in nonessential regions of the enzyme. In contrast, 2 other substitutions, known to cause the type II form of the disease, were found to directly affect the consensus FAD-binding site or indirectly influence NADH binding. Thus, these data support the idea that enzyme inactivation is a cause of the type II disease, whereas enzyme instability may lead to the type I form.

Sequence analysis of the immunoglobulin antigen receptor of hepatitis C virus–associated non-Hodgkin lymphomas suggests that the malignant cells are derived from the rheumatoid factor–producing cells that occur mainly in type II cryoglobulinemia

Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3578-3584 ◽  
Author(s):  
Valli De Re ◽  
Salvatore De Vita ◽  
Alessandra Marzotto ◽  
Maurizio Rupolo ◽  
Annunziata Gloghini ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Rheumatoid Factor ◽  
Light Chain ◽  
Mixed Cryoglobulinemia ◽  
Amino Acid Sequences ◽  
Type Ii ◽  
E2 Protein ◽  
Immunoglobulin Receptor

Analysis of the immunoglobulin receptor (IGR) variable heavy- and light-chain sequences on 17 hepatitis C virus (HCV)-associated non-Hodgkin lymphomas (NHLs) (9 patients also had type II mixed cryoglobulinemia [MC] syndrome and 8 had NHL unrelated to MC) and analysis of intraclonal diversity on 8 of them suggest that such malignant lymphoproliferations derive from an antigen-driven pathologic process, with a selective pressure for the maintenance of a functional IgR and a negative pressure for additional amino acid mutations in the framework regions (FRs). For almost all NHLs, both heavy- and light-chain complementarity-determining regions (CDR3) showed the highest similarity to antibodies with rheumatoid factor (RF) activity that have been found in the MC syndrome, thus suggesting that a common antigenic stimulus is involved in MC syndrome and in HCV-associated lymphomagenesis. Moreover, because HCV is the recognized pathologic agent of MC and the CDR3 amino acid sequences of some HCV-associated NHLs also present a high homology for antibody specific for the E2 protein of HCV, it may be reasonable to speculate that HCV E2 protein is one of the chronic antigenic stimuli involved in the lymphomagenetic process. Finally, the use of specific segments, in particular the D segment, in assembling the IgH chain of IgR seems to confer B-cell disorders with the property to produce antibody with RF activity, which may contribute to the manifestation of an overt MC syndrome.

scholarly journals The amino acid sequence of component 7c, a type II intermediate-filament protein from wool

1989 ◽  
Vol 261 (3) ◽  
pp. 1015-1022 ◽  
Author(s):  
L G Sparrow ◽  
C P Robinson ◽  
D T W McMahon ◽  
M R Rubira
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Intermediate Filament ◽  
Coiled Coil ◽  
British Library ◽  
Intermediate Filament Protein ◽  
Type I ◽  
Type Ii ◽  
Blocking Group ◽  
Intermediate Filament Proteins

Component 7c is one of the four homologous type II intermediate-filament proteins that, by association with the complementary type I proteins, form the microfibrils or intermediate filaments in wool. Component 7c was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage reactions. It is an N-terminally blocked molecule of 491 residues and Mr (not including the blocking group) of 55,600; the nature of the blocking group has not been determined. The predicted secondary structure shows that component 7c conforms to the now accepted pattern for intermediate-filament proteins in having a central rod-like region of approximately 310 residues of coiled-coil alpha-helix flanked by non-helical N-and C-terminal regions. The central region is divided by three non-coiled-coil linking segments into four helical segments 1A, 1B, 2A and 2B. The N-and C-terminal non-helical segments are 109 and 71 residues respectively and are rich in cysteine. Details of procedures use in determining the sequence of component 7c have been deposited as a Supplementary Publication SUP 50152 (65 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1989) 257,5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 7c, peptides CN1, CN2 and CN3, and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, (3) details of methods used to determine the C-terminal sequence of peptide CN3, and (4) detailed evidence to justify a number of corrections to the previously published sequence.

scholarly journals The lspA Gene, Encoding the Type II Signal Peptidase of Rickettsia typhi: Transcriptional and Functional Analysis

2006 ◽  
Vol 189 (2) ◽  
pp. 336-341 ◽  
Author(s):  
M. Sayeedur Rahman ◽  
Shane M. Ceraul ◽  
Sheila M. Dreher-Lesnick ◽  
Magda S. Beier ◽  
Abdu F. Azad
Keyword(s):  
Amino Acid Sequences ◽  
Signal Peptidase ◽  
Secretory Proteins ◽  
Transcriptional Level ◽  
Temperature Sensitive ◽  
Type I ◽  
Type Ii ◽  
Intracellular Growth ◽  
Rickettsia Typhi ◽  
Differential Expression Pattern

ABSTRACT Lipoprotein processing by the type II signal peptidase (SPase II) is known to be critical for intracellular growth and virulence for many bacteria, but its role in rickettsiae is unknown. Here, we describe the analysis of lspA, encoding a putative SPase II, an essential component of lipoprotein processing in gram-negative bacteria, from Rickettsia typhi. Alignment of deduced amino acid sequences shows the presence of highly conserved residues and domains that are essential for SPase II activity in lipoprotein processing. The transcription of lspA, lgt (encoding prolipoprotein transferase), and lepB (encoding type I signal peptidase), monitored by real-time quantitative reverse transcription-PCR, reveals a differential expression pattern during various stages of rickettsial intracellular growth. The higher transcriptional level of all three genes at the preinfection time point indicates that only live and metabolically active rickettsiae are capable of infection and inducing host cell phagocytosis. lspA and lgt, which are involved in lipoprotein processing, show similar levels of expression. However, lepB, which is involved in nonlipoprotein secretion, shows a higher level of expression, suggesting that LepB is the major signal peptidase for protein secretion and supporting our in silico prediction that out of 89 secretory proteins, only 14 are lipoproteins. Overexpression of R. typhi lspA in Escherichia coli confers increased globomycin resistance, indicating its function as SPase II. In genetic complementation, recombinant lspA from R. typhi significantly restores the growth of temperature-sensitive E. coli Y815 at the nonpermissive temperature, supporting its biological activity as SPase II in prolipoprotein processing.

Sequence and expression of a type II keratin, K5, in human epidermal cells

1988 ◽  
Vol 8 (1) ◽  
pp. 486-493
Author(s):  
R Lersch ◽  
E Fuchs
Keyword(s):  
Human Gene ◽  
Basal Layer ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Type I ◽  
Type Ii ◽  
Gene Encoding ◽  
Human Epidermal Cells ◽  
Rna Blot Analysis

We report here the cDNA and amino acid sequences of a human 58-kilodalton type II keratin, K5, which is coexpressed with a 50-kilodalton type I keratin partner, K14, in stratified squamous epithelia. Using a probe specific for the 3'-noncoding portion of this K5 cDNA, we demonstrated the existence of a single human gene encoding this sequence. Using Northern (RNA) blot analysis and in situ hybridization with cRNA probes for both K5 and K14, we examined the expression of these mRNAs in the epidermis and in cultured epidermal cells. Our results indicate that the mRNAs for K5 and K14 are coordinately expressed and abundant in the basal layer of the epidermis. As cells undergo a commitment to terminally differentiate, the expression of both mRNAs seems to be downregulated.

DNA sequence analysis of a mouse pro alpha 1 (I) procollagen gene: evidence for a mouse B1 element within the gene

1982 ◽  
Vol 2 (11) ◽  
pp. 1362-1371
Author(s):  
J M Monson ◽  
J Friedman ◽  
B J McCarthy
Keyword(s):  
Amino Acid ◽  
Dna Sequence ◽  
Repetitive Sequences ◽  
Rna Polymerase Iii ◽  
Amino Acid Sequences ◽  
Type I ◽  
Base Pairs ◽  
Coding Sequences ◽  
Splice Junctions ◽  
I Gene

In a 3.8-kilobase mouse DNA sequence encoding amino acid sequences for the pro alpha 1(I) chain of type I procollagen, 14 coding sequences were identified which specify a sequence 95% homologous to amino acid residues 568 to 963 of the bovine alpha 1(I) chain. All of these coding sequences were flanked by appropriate splice junctions following the GT/AG rule. These observations suggest, but do not prove, that this pro alpha 1(I) gene is transcriptionally active. Of the 14 coding sequences, 7 were 54 base pairs in length, whereas the remainder were higher multiples of 54 base pairs. Nonrandom utilization of codons pertained throughout all of the coding sequences showing a preference (56%) for U in the wobble position. Two of the intervening sequences encoded imperfect vestiges of coding sequences which exhibited a codon preference different from that of the pro alpha 1(I) gene proper and were not flanked by splice junctions. One intervening sequence encoded a member of the mouse B1 family of middle repetitive sequences. It was flanked by 8-base-pair direct repeats and had a truncated A-rich region, suggesting that it may be a mobile element. Within this element were sequences which could function as a RNA polymerase III split promoter.

scholarly journals The complete cDNA and deduced amino acid sequence of a type II mouse epidermal keratin of 60,000 Da: analysis of sequence differences between type I and type II keratins.

1984 ◽  
Vol 81 (18) ◽  
pp. 5709-5713 ◽  
Author(s):  
P. M. Steinert ◽  
D. A. Parry ◽  
E. L. Racoosin ◽  
W. W. Idler ◽  
A. C. Steven ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Type I ◽  
Type Ii

scholarly journals Role of Transmembrane Domain and Cytoplasmic Tail Amino Acid Sequences of Influenza A Virus Neuraminidase in Raft Association and Virus Budding

2004 ◽  
Vol 78 (10) ◽  
pp. 5258-5269 ◽  
Author(s):  
Subrata Barman ◽  
Lopa Adhikary ◽  
Alok K. Chakrabarti ◽  
Carl Bernas ◽  
Yoshihiro Kawaoka ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Influenza A ◽  
Transmembrane Domain ◽  
Amino Acid Sequences ◽  
Type Ii ◽  
Virus Growth ◽  
Transmembrane Glycoprotein ◽  
Virus Life Cycle

ABSTRACT Influenza virus neuraminidase (NA), a type II transmembrane glycoprotein, possesses receptor-destroying activity and thereby facilitates virus release from the cell surface. Among the influenza A viruses, both the cytoplasmic tail (CT) and transmembrane domain (TMD) amino acid sequences of NA are highly conserved, yet their function(s) in virus biology remains unknown. To investigate the role of amino acid sequences of the CT and TMD on the virus life cycle, we systematically mutagenized the entire CT and TMD of NA by converting two to five contiguous amino acids to alanine. In addition, we also made two chimeric NA by replacing the CT proximal one-third amino acids of the NA TMD [NA(1T2N)NA] and the entire NA TMD (NATRNA) with that of human transferrin receptor (TR) (a type II transmembrane glycoprotein). We rescued transfectant mutant viruses by reverse genetics and examined their phenotypes. Our results show that all mutated and chimeric NAs could be rescued into transfectant viruses. Different mutants showed pleiotropic effects on virus growth and replication. Some mutants (NA2A5, NA3A7, and NA4A10) had little effect on virus growth while others (NA3A2, NA5A27, and NA5A31) produced about 50- to 100-fold-less infectious virus and still some others (NA5A14, NA4A19, and NA4A23) exhibited an intermediate phenotype. In general, mutations towards the ectodomain-proximal sequences of TMD progressively caused reduction in NA enzyme activity, affected lipid raft association, and attenuated virus growth. Electron microscopic analysis showed that these mutant viruses remained aggregated and bound to infected cell surfaces and could be released from the infected cells by bacterial NA treatment. Moreover, viruses containing mutations in the extreme N terminus of the CT (NA3A2) as well as chimeric NA containing the TMD replaced partially [NA(1T2N)NA] or fully (NATRNA) with TR TMD caused reduction in virus growth and exhibited the morphological phenotype of elongated particles. These results show that although the sequences of NA CT and TMD per se are not absolutely essential for the virus life cycle, specific amino acid sequences play a critical role in providing structural stability, enzyme activity, and lipid raft association of NA. In addition, aberrant morphogenesis including elongated particle formation of some mutant viruses indicates the involvement of NA in virus morphogenesis and budding.

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